Spending only 2 days in Budapest should be a crime. However, I do understand if you’re just passing through or you’re pressed for time. I guess I can forgive you if that’s the case; but don’t let it happen again.
Budapest is very well known for their Thermal Baths, Sparty, Sziget Festival, and Ruin Pubs. However one of their funnest and most adventurous activities still seems to be bit of a hidden treasure(literally). Those same hot springs that supply the thermal baths have also formed miles and miles of caves under Buda.