The Petrova House is located somewhere in the country of Bulgaria. It was owned by the Petrova Family, which included Katerina Petrova, her parents, and all of her siblings.
Katerina was born in this house in 1473, and lived in the house for seventeen years. In 1490, Katerina gave birth to a baby girl, but Katerina's father gave her baby away to another family as soon as she was born. Katerina was then disowned and banished from Bulgaria by her parents for the shame she had brought her family by having a baby out of wedlock. In 1492, she returned as a newly-turned vampire only to find the bloodied bodies of everyone in her family. They had been all killed by Klaus as revenge for Katherine betraying him by going on the run and becoming a vampire so he couldn't sacrifice her to break his curse.