Den­ver zoo’s pride is Bear Moun­tain, cre­at­ed using casts of actu­al Col­orado rock out­crop­pings to sim­u­late the bears’ nat­ur­al habi­tat. For a dif­fer­ent way to watch the wildlife, hop on the Pio­neer Train, the first train in a U.S. zoo to be pow­ered by nat­ur­al gas. Oth­er exhibits include an indoor rain­for­est and the 7‑acre Pri­mate Panora­ma.