The Hydro Grill, located in Calistoga, offers a happy hour with excellent discounts on the food, which by the way is delicious. It is located in a brick building, also known as the "brick building on the corner," and offers a casual environment in a historic building. You'll find plenty of seating because happy hour is available to you anywhere, not just at the bar. It's worth noting that there aren't a ton of establishments offering cocktails beyond standard well drinks on their happy hour menu, but the Hydro Grill has 5 on their menu! Also, if you're looking for the cheapest well drinks in the Napa Valley you'll find them here: only $5!!  Now that's some great hydrotherapy! We tried 3 cocktails and 3 apps and all were excellent, but the most notable cocktail was the Calistoga Chill, which we enjoyed on a very hot day! As for the best app, mac and cheese is always a winner. Check for live music on Sundays.