Upano — Southern Sangay Hypothetical Terrace Extension
Upano South Terrace Hypothesis · Sangay Foothill Hypothetical Urban Expansion
Hypothesized Sangay phase (800–1400 CE) if cultural·Hypothesized Sangay Huapula (if verified)·🇪🇨 Morona-Santiago Province, Sangay foothills 3.8 km south of verified Huapula southern platform, Santiago–Upano interfluve, Ecuador
About
About Upano — Southern Sangay Hypothetical Terrace Extension
8 km beyond the verified Huapula southern platform (Rostain 2024 mapped limit). On Maxar hillshade and ALOS-PALSAR, 14 faint rectilinear 25–30 m crop marks suggest mounds, and a 7-m-wide linear hints at causeway continuation upslope onto colluvial footslope where Kilamope–Upano platform architecture would be hydrogeologically improbable (slope 12–15° vs verified 2–3°). No ground truth or LiDAR strip covers this ridge as of 2024; INPC warns the marks may be Sangay lahars or 1970s pasture terracing.
If verified, it would add 12 ha and extend Upano urbanism 4 km further onto Andean flank — a 30% expansion — challenging the valley-floor agrarian model. Until LiDAR and test pitting confirm Sangay tephra-sealed cultural layers, the extension remains contested (included for completeness following verification taxonomy).
Why it mattersTests Upano model limits: if foothill mounds verified, Upano urbanism would be ridge-hill not just valley-floor agrarian, revising carrying capacity 30%. Until then it illustrates remote-sensing over-interpretation risk opposite to Kuhikugu phantom — understudied edge vs overstudied mirage.
Open questions
Mysteries & theories
Mysteries
- 01Whether ridge marks are lahars, pasture terraces or true Sangay mounds
- 02If real, how water managed on 12° colluvium without terra preta
Theories
- 01Skeptical view: 12° slope and colluvium make platform agriculture hydrologically impossible — extension is pareidolia
Theories are interpretations, not findings. The seal above tells you how much scholarly weight the place carries.
History
How it came to be
- Built
- Hypothesized c.300–600 CE Sangay-phase extension if real
- Period
- Hypothesized Sangay phase (800–1400 CE) if cultural
- Culture
- Hypothesized Sangay Huapula (if verified)
- Builders
- Hypothesized Upano–Kilamope footslope builders
- Purpose
- Hypothetical ridge-town foothill expansion controlling Santiago interfluve pass
- Abandoned
- Hypothesized 1400 CE if existed
- Rediscovered
- 2024 Maxar hillshade speculation by regional enthusiasts; no CNRS LiDAR strip
- Excavation
- Unexcavated
2024
Maxar hillshade enthusiasts flag 14 rectilinear marks 3.8 km south of Huapula
2024
Rostain team notes marks lie outside 2024 LiDAR coverage; no ground check
2025
INPC classifies extension as contested pending LiDAR and test pits
On the ground
Structures & features
2.1785° S · 78.0122° W · 680 m · 3 mapped features
Contested Foothill Rectilinear Marks (14)
hypothetical mound14 faint 25–30 m rectilinear crop marks on 12° colluvium — may be lahars
2.1788° S · 78.0125° WLinear Trace (7 m × 320 m)
hypothetical causewayFaint 7 m linear suggestive of causeway continuation — may be cattle track
2.1782° S · 78.0119° WSangay Lahar Boulders on Slope
geological markerNatural lahar boulder field that could mimic mound edges
2.1785° S · 78.0122° W