La Gruta Restaurant & Spa, a 20-minute drive from San Miguel de Allende's Centro, is said to be the most popular of the region's natural hot springs.
On a spacious, well-treed lot, spring fed pools - from tepid to warm and warmer - are the main focus. A covered. water-filled tunnel leading to an enclosed cave-like pool was the favorite feature. This domed grotto is also the pool with waters that are closest to "hot." Along with the pools, you'll find pool-side lounge chairs and patio areas set up with tables and chairs. There's also an all-day, outdoor restaurant serving dishes such as omelet’s, fruit and yogurt, salads, sandwiches and tuna-stuffed avocado.
Tunnel leads to the hot water source
Large heated pool with underwater seats
La Gruta is not fancy - change rooms, washrooms and massage facilities are clean but basis. Also, this is a family place so don't go expecting total peace and quiet, especially during holidays and weekends.
In Moon's San Miguel de Allende guidebook, Julie Doherty Meade writes: For the most Zen experience, get there early in the morning as the pools are just filling up with fresh water and few people have arrived.
If you're interested in "taking the waters" La Gruta is certainly worth a half-day visit. Allow 90-minutes at the very least.