Our Green Tortoise South Park Loop Trip, Sept., 1998. Where: Big Bend Park, swimming and soaking in the Rio Grande. This is the best swimming hole I have ever been to. A swift, safe river to swim in, deep enough for jumping off the bank, with a hot springs tub to soak in at the river's edge. Further up the bank is a gem of a soak...a hot springs inside a bamboo cavern. Combine it with a day of blue-sky and upper 90's (F) temperature, and you have the pre-cursor for a wild evening 'back at the ranch' thanks to the La Kiva Bar nearby. Many passengers did just that. Click on photos to see full screen view. Rio Grande swimming hole. Hot springs in foreground, Rio Grande swimming in the background. Bamboo cave, with hotsprings at the end.