Wakamatsu Onsen:

Located next to Minami Koen and easily accessible by car and bicycle. Walking takes about 15min from JR Okazaki station.

Open every day of the week except for every first and third monday of the month, usually closed when a taifun is coming.
Admission 450yen from monday to friday and 500yen on saturday and sunday. Opens at 10am and closes at 12:30pm with the latest admission up until 12:00pm.
Tel: 71-3726

How to get there:
Follow the Route 248 going south towards Gamagori. At the crossroads where Mosburger is located, turn right and go down that small alley. Turn right again, follow the road uphill and turn left. You will be able to see the onsen from the left side from there.