OK our trip was at the end of July - the middle of winter. The day before it had rained in the valley so the 14 KM drive on a wet gravel road was an adventure by itself. There were sections that from the freeze-thaw-rain action were very loose sloppy mud and on STEEP hills. One section, My car was sliding all over and the raging river was to our right and straight down.
On the way out we used the snow traction control on the rental car and it made the trip a LOT easier.
We finally made it safely and what a great set up! They have a bunch of pools that collect the hot run off and mix it with cold water to keep the temperature stable. Even in the winter there were a lot people so locker room space is at a premium. Leave valuables locked in car - they have a staff of people in parking lot- and bring a backpack.
If you own or manage Termas Geometricas, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.