Emerald Wading Pool

From Memory Alpha, the free Star Trek reference

Emerald Wading Pools were a well known leisure attraction. Pools were located on both Cirrus IV and Sumiko III.

A holographic representation of the pool on Cirrus IV was among the holodeck programs available for use on the USS Enterprise-D. It was recommended to Kristin by Doctor Beverly Crusher, who thought it would be safer than a recreation of the Cliffs of Heaven on Sumiko IV. (TNG: "Conundrum")

A simulation of the pool on Sumiko III was also available aboard the USS Enterprise-E in 2373. (Star Trek: First Contact)