Just because you said medieval ruins, I'm much more impressed with the medieval buildings that aren't ruins. Definitely worth looking into some of these less well know places if you ever plan a trip, or just want to look up some cool pictures.

For US people, the thing thats most impressive, is that all of these were built before Christopher Columbus even started his voyage to the americas in 1492.

Ye Olde Trip to Jerusalem, Nottingham - Established around 1189, makes it approximately 835 years old. The pub is partially built into the sandstone caves beneath Nottingham Castle. Still a great looking and fully functioning pub today, I want to go there.

Anne Hathaways Cottage, Stratford-upon-Avon, Warwickshire - Dates back to about 1463, which makes it around 560 years old. A very British medieval farmhouse and the childhood home of William Shakespeare's wife.

Stokesay Castle, Shropshire - Was built in the late 13th century, around 1291, which makes it over 730 years old. It's one of the best preserved fortified manor houses in England.

Monnow Bridge, Monmouth, Wales - Was built in the late 13th century, around 1272-1297, making it about 725 years old. It’s the only remaining fortified river bridge in Britain with its gate tower intact.

St. Ives Bridge, Cambridgeshire - Built in the 1400s, making it around 600 years old. The bridge has a full chapel in the middle.