High-resolution seismicity data from Costa Rica and southern Nicaragua have been used to image the geometry of the Wadati-Benioff zone under southern Central America. The data include 9514 events with computed horizontal and vertical errors smaller than 4 and 5 km respectively. We found that under the Nicaragua-Costa Rica border the Wadati-Benioff zone contorts (from steep to shallow dip angles, northwest to southeast) but does not show evidence of a brittle test, as postulated by others. Further to the southeast-northeast from Puerto Caldera-the Wadati-Benioff zone does, however, show a tear (the Quesada Sharp Contortion) at intermediate depths (h >70 km). Overall the dip angle of the Wadati-Benioff zone decreases from 84° under Nicaragua to 60° under central Costa Rica. This geometry of the Wadati-Benioff zone and other tectonic features related to the subduction of the Cocos plate beneath the Caribbean plate have been integrated into a model that correlates them with along-trench variations in age of the subducted Cocos plate. -from Authors