Octagons KML This KML file focuses on the geodetic interrelationships of the octagon earthworks in North and South America. In 2005, I acquired GPS data at the Newark Earthworks. I first placemarked the octagon geoglyph in the Amazon in 2010, naming it Acre Octagon. The 2010.06.30 Google Earth satellite image clearly shows the 150meterwide outline in a pasture. Illegal damage by agricultural plowing is evident in the 2016 satellite image. In May of 2022, when I finally examined the interrelationship of the Acre Octagon with Newark Octagon in Ohio, I noted the cosine of their arc distance equals phi. I should have examined this relationship a decade earlier. In the summer of 2024 when updated satellite imagery in Google Earth allowed new survey of deforested areas I noticed another octagon geoglyph, this one in Amazonas. Amazonas Octagon is the same size as Acre Octagon and its spatial relationship to Newark Octagon also expresses the value of Phi and phi, in this case the phi ratio is expressed by the colatitudes of the sites, their distances to their respective poles. I have edited this KML to include the newly recorded octagon and new findings. 
Observatory Mound to Acre Octagon 155m noomacroc arc distance 51.827238° cosine = 0.618035 (6m) phi ratio 1.0 : 0.618034 = 1.618034 : 1.0 
Octagon Small Circle  Amazonas Octagon 155m noscamaoc colatitude ratio = 1.0 : 0.618037 (+25m) 
Sites included below are not inclusive of all monuments considered in the results folder. My Archaeogeodesy Placemarks, Ancient Monuments in Google Earth KML file displays all the sites. Downloads:
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Acre Octagon 155m 9.895957 67.519215 188 destroyed, plowed 
Amazonas Octagon 155m 9.183614 67.002622 165 
Amazonas Quadrangle 175m 9.182625 67.005123 171 
Newark Octagon 40.05469583 82.44426250 GPS average of 8 vertices

Newark Observatory Circle 40.05207671 82.44861007 Calculated per 3 GPS readings and survey data. Observatory Circle arcs viewed from Observatory Mound. At Newark Earthworks, Observatory Circle is attached to the Octagon. The Great Circle stands apart to the southeast, with Newark's two great circles aligned to Marietta Earthworks. 
Newark Octagon Observatory Mound 40.05113889 82.45013889 GPS 5m Web Archive 
Newark Octagon Gateway 40.053222 82.446715 mean of 4 GPS readings Newark Octagon Work Photo Gallery 
Newark Octagon Vertex E 40.05597222 82.44219444 GPS 5m 
Newark Octagon Small Circle 40.05250000 82.44325000 GPS 2m 
High Bank Octagon 39.297306 82.917519 194 
Poverty Point Earthworks 32.636426 91.403277 27

The Phi ratio in relation to Newark was well evidenced prior to noticing any relationship to the Acre Octagon. When satellite imagery revealed the Amazonas Octagon I immediately checked the relationship to Newark Octagon. I was not the least surprised to see another phi expression or the ratio expressed in relation to the poles given the Acre and Newark octagons having a twotoone distance relationship to the north pole. There was a surprise, the two Amazon octagons are the same size. 
Golden Mean Longitude Ratios Stated simply, the golden mean or golden ratio divides a line such that the whole is proportional to the longer part as the longer part is to the shorter part. The formula x : 1 = 1 : x + 1, stated numerically is 0.618034. : 1.0 = 1.0 : 1.618034, where Phi like pi is an infinite irrational number (1.6180339887...). Upper case Phi is 1.618... and lower case phi is 0.618..., Phi  1 = phi. The golden ratio obtains from a triangle with sides 2 : 1 and thus a hypotenuse equaling the square root of five. The values equate to half of two sides, [(the square root of five plus one) divided by two] and to [(square root of five minus one) divided by two]. Also, Phi squared equals Phi plus one. The x  1 = y and x + 1 = y formulations have relevance in the astronomy equations. 
Observatory Mound  Acre Octagon arc 51.827238° cosine = 0.618035 (6m) phi ratio 1.0 : 0.618034 = 1.618034 : 1.0 
Observatory Circle  Acre Octagon noccacroc arc 51.827748° cosine = 0.618028 (+51m) 
Observatory Circle  Acre Octagon  North Pole noccnpoleacroc arcs ratio @ npole = 1.0 : 0.499999 (6m) 
Observatory Circle  Acre Octagon  North Pole noccacrocnpole arcs ratio @ npole = 1.0 : 0.499999 (6m) 
Observatory Mound  Acre Octagon noomacroc arc 51.827238° cosine = 0.618035 (6m) 
51.8273° cosine = 0.618034 My GPS readings produced a 51.52° azimuth from the center of Observatory Mound to the gateway at the opposite apex of the Octagon work (noom +/5m to noe +/5m, 863m arc). The arc distance from the Newark Octagon's Observatory Mound to the Acre Octagon (noomacroc) equals 51.827238° (cosine = 0.618035). The angle's cosine equals phi (51.827292° cosine = 0.618034...), which matches both the earthwork's azimuth and the lunar major azimuth. Observatory Mound lunar major for 462 C.E. = 51.8273° (474 C.E. at the Octagon centerpoint). Middleton reported a 51.45° azimuth for the Observatory Circle and a mean of 51.98° for the parallel earth banks between the Octagon and Observatory Circle. According to Thomas (1894), the Octagon's azimuth is 52.15° E. of N. A four to pi right triangle has a 51.854° angle. A four to five right triangle has a 51.34° angle. My 2006 webpage Temporal Epoch Calculations discusses the Newark Octagon azimuth, the lunar major alignment, and possible interpretations. 

Observatory Circle  Amazonas Quadrangle 175m colatitude ratio = 1.0 : 0.618034 (+4m) phi ratio 1.0 : 0.618034 = 1.618034 : 1.0 
Octagon Small Circle  Amazonas Octagon 155m noscamaoc colatitude ratio = 1.0 : 0.618037 (+25m) 
Baseline determined by Amazonas Octagon latitude. amaoc colatitude times phi equals 49.947273 degrees. 49.947273 degrees colatitude equals 40.052727 degrees latitude. 
Baseline determined by Observatory Circle latitude. nocc colatitude times Phi equals 80.817438 degrees. 80.817438 degrees colatitude equals 9.182562 degrees latitude. 
Octagon Gateway  Poverty Point Earthworks  Acre Octagon ew ratio @ nocg = 1.0 : 0.600004 (+7m) ew ratio @ acroc = 1.0 : 0.624998 (4m) ew ratio @ acroc = 8.000021 : 5.0 (4m) 
Great Circle  Poverty Point A  Rio Branco Double Quadrangle ew ratio @ ncec = 1.0 : 0.618044 (+10m) ew ratio @ rbrdq = 1.0 : 0.618030 (10m) 
Observatory Circle  High Bank Octagon  Acre Octagon ew ratio @ nocc = 1.0 : 0.031409 (12m) pi to 8 decimals = 3.14159265 
Newark Octagon Gateway  Machupicchu Tres Portales  Amazonas Octagon 155m ns ratio @ nocga = 1.0 : 0.925199 (+4m) epoch hopewell ml = 0.9251987 moons per lunar orbit ns ratio @ mactp = 1.0 : 0.074801 (4m) epoch hopewell ol = 0.0748013 orbits per lunar orbit ns ratio @ amaoc = 1.0 : 0.080848 (4m) epoch hopewell om = 0.08084893 orbits per moon 
Observatory Mound  Intiwatana UTM  Amazonas Quadrangle 175m noomintihamaq55 ns ratio @ noom = 1.0 : 0.925199 (+2m) 
Octagon Small Circle  Machupicchu Tres Portales  Amazonas Octagon 155m noscmactpamaoc ns ratio @ nosc = 1.0 : 0.925198 (2m) 
Machupicchu Courtyard  Chavin Plaza  Acre Octagon ew ratio @ mapic = 1.0 : 0.921496 (+2m) epoch inca mn = 0.921493 moons per lunar nodal period 
Waynapicchu  Chavin Plaza Circular  Acre Octagon ew ratio @ mwayn = 1.0 : 0.921503 (+6m) 
Intiwatana UTM  Chavin Plaza Circular intihchhpc arc : ns ratio = 1.0 : 0.618027 (5m) phi ratio 1.0 : 0.618034 = 1.0 : 1.618034 
Newark Octagon  Sechin Alto Cuarto  Amazonas Octagon 155m ew ratio @ nocp = 1.0 : 0.272125 (+5m) epoch hopewell dn = 27.2122219 days per lunar nodal period 
Sechin Alto Cuarto  Chavin Lanzon  Huascarán GPS ns ratio @ chhla = 1.0 : 0.272113 (0.5m) 
Sechin Alto Plaza  Acre Octagon 155m  Garopaba Sambaqui ew ratio @ sealp = 1.0 : 0.365243 (+2m) epoch hopewell dy = 365.2423969 days per year Largest shell mound in the Santa Catarina area, in volume nearly equal to Monks Mound. Wikimedia Commons 
Sechin Alto Sala  Chavin Plaza Circular  Acre Octagon 155m arcs ratio @ secas = 1.0 : 0.099999 (1.5m) arcs ratio @ secas = 10.00013 : 1.0 (1.5m) 
Sechin Alto Sala  Chavin Portal  Acre Octagon 155m secaschhapacroc arcs ratio @ chhap = 1.0 : 0.111094 (18m) secaschhapacroc arcs ratio @ secas = 1.0 : 0.100011 (+13m) 
Acre Octagon 155m  Amazonas Octagon 155m  Taukachi Circular Plaza ns ratio @ acroc = 1.0 : 0.618205 (+13m) ns ratio @ takcp = 1.0 : 0.617586 (22m) ns ratio @ amaoc = 1.0 : 2.619207 (13m) 
Observatory Mound  Huaca del Sol Centerline  Acre Octagon ns ratio @ hdscl = 1.0 : 0.036624 (1m) epoch hopewell ry = 366.242358 rotations per year 
Newark Octagon  Huaca del Sol  Acre Octagon nocphdsolacroc ns ratio @ hdsol = 1.0 : 0.036629 (+17m) epoch hopewell ro = 366.2564674 rotations per orbit 
Newark Octagon Gateway  Cochasqui Pyramid  Amazonas Octagon 155m ew ratio @ cochp = 1.0 : 0.366241 (1m) epoch hopewell ry = 366.2423584 rotations per year 
Newark Octagon  Amazonas Octagon 155m  Cerro Quitoloma nocpamaoccquit ew ratio @ nocp = 1.0 : 0.273969 (+7m) epoch hopewell rl = 27.3964671 rotations per lunar orbit Web Archive Web Archive 
Links, Readings: Hundreds of Geoglyphs Discovered in the Amazon  Database: amazon_geoglyphs.xlsNewark Archaeogeodesy Assessing Evidence of Geospatial Intelligence in the Americas Temporal Epoch Calculations An introduction to research considerations regarding temporal variations in archaeoastronomical and archaeogeodetic variables. ©2006 Ancient Earthworks of Eastern North America. Newark Earthworks has been termed the largest geometric earthwork in the world. Newark Octagon Earthworks, the largest single North American geometric earthwork form at 2898.5 feet long. Ancient Monument Phi Ratios KML file. Phi monument relationships of Newark, Machupicchu, Tikal, Piramide del Sol, Cahokia, Poverty Point, Huascaran, Huaca de la Luna, Chan Chan, Pachacamac, Chavin, Sillustani, Tiwanaku, Acre Triple Square, Tumi Chucua Zanja, and Loma X. 