Mexico, Yucatan -- Geologist Ben Miller, 42, visited Cancun with his wife Beth and their two children. The children were mainly interested in the beach, snorkeling and such. But Beth had studied the Mayan culture for half a year from books on her mini iPad. She directed them to all the pyramids and sites.
In the hotel lobby Ben spotted for a day tour of Aktun-Chen. He knew they had one rest day. When he showed the kids the zip line feature, Beth was immediately out voted three to one.
They set off and Beth decided to do the zip line and jungle tour too. "So the kids will be safe."
This left Ben to explore the underground river on his own. There was a snorkeling part too, but the kids were "all snorkeled out" for this trip.
"It's just lime stone. Many times the roofs of these underground rivers collapse. It still leaves a wonderful cistern for rain water and keeps the water during drought. I'm sure it's in one of them Maya books Beth has. It's all lime stone. So is everything here, including the pyramids."