AKTUN TUYUL CAVE SYSTEM, Mexico -- Rays of sunlight slice through pools of crystal water as clusters of fish cast shadows on the limestone below. Arching over the emerald basin are walls of ...

AKTUN TUYUL CAVE SYSTEM, Mexico (AP) — Rays of sunlight slice through pools of crystal water as clusters of fish cast shadows on the limestone below. Arching over the emerald basin are walls of ...

In other caverns, the concrete filling the pillars has spilled out to coat the limestone ground. Water showed traces of iron pollution by rust coming from the metal.

AKTUN TUYUL CAVE SYSTEM, Mexico (AP) — Rays of sunlight slice through pools of crystal water as clusters of fish cast shadows on the limestone below. Arching over the emerald basin are walls of… ...

Engineer Guillermo D. Christy collects water samples while sitting next to a steel pillar filled with concrete, installed to support a part of the Maya Train track, inside the Aktun Tuyul cave ...

Aktun Tuyul Cave System, MEXICO (AP) — Rays of sunlight slice through pools of crystal water as clusters of fish cast shadows on the limestone below. Arching over the emerald basin are walls of ...

Caves are mysterious areas which depict the lifestyle of ancient times through paintings and carvings on the walls. These ...

A team of experts from Kim Il Sung University, Kim Chaek University of Technology, the National Authority for the Protection ...

AKTUN TUYUL CAVE SYSTEM, Mexico (AP) — Rays of sunlight slice through pools of crystal water as clusters of fish cast shadows on the limestone below. Arching over the emerald basin are walls of ...

AKTUN TUYUL CAVE SYSTEM, Mexico (AP) — Rays of sunlight slice through pools of crystal water as clusters of fish cast shadows on the limestone below. Arching over the emerald basin are walls of ...