The Spis Castle is about a 30 minute drive from Poprad. The drive is one of the most scenic drive. There is free parking as you arrive and then it's about a 10 minute walk up to the castle entrance. Be prepared to for a tough walk. I would not recommend this for older people or kids who have tendency to ask you to pick them up a thousands times.
The Castle is open from 9am to 7pm and they charge 8euros for adults and 4 for kids. They also provide guided tour but not available in english but the lady would tell you to ask the guide to explain it english and most would do it. You can also get a audio guide which is available in English.
We've been chasing castles for the past few days and i have to be honest. I don't get too excited by a castle or a church anymore but regardless, it is one of the most prettiest castles i've seen.
The whole tour will take you about an hour and it is absolutely worth it. We've ran into two kids begging for money and you can see them at the beginning of the vide0 as you come up. We decided to give one kid 5 euros and asked them to split it between them. I don't think they understood anything but the other kid literally walked and asked us for money all the way down. My recommendation is that you don't entertain the kids. I'm saying this because i was stressed out during the whole descent wondering if they would try to do anything even thou i know they won't. You can't be careful enough when you are with two young kids.