Tetra Yukawa is a very cheap and good hot spring.

If you are looking for a more upscale hotel, I recommend the Hakodate House“Emi Hakodate ya”.

https://www.google.co.jp/maps/place/Hotel+Tetra+Yunokawaonsen/@41.7764539,140.7929812,15z/data=!4m2!3m1!1s0x0:0x44ed97305872b55b?sa=X&ved=2ahUKEwjo76WMhfvtAhXay4sBHVQwArcQ_BIwDHoECBsQBQ

https://www.google.co.jp/maps?q=大沼公園&oe=UTF-8&client=safari&safe=images&um=1&ie=UTF-8&sa=X&ved=2ahUKEwjK3vLYrP_tAhU0yosBHaTMA04Q_AUoAXoECAUQAw

http://onumakouen.com/#parentHorizontalTab2