El Tintero — the inkwell — is the most enigmatic structure on the site. An inverted cone shape unlike anything else at Kuelap, its purpose remains unknown. Current theories suggest it may have served as a mausoleum or a ritual space, but the evidence is thin. Whatever its function, it is the building that stays with you longest: strange and quietly unsettling, it sits near the northern end of the citadel and is worth seeking out.