The "Turkish Tower" of Perušić wasn't built by the Turks. Rather, it was built when the town was founded by the Perušić brothers. When the Ottoman Turks conquered the area they, naturally, didn't let a perfectly good fortification go to waste. Similarily, the neighboring Church of the Exhaltation of the Holy Cross was used as a mosque.
When the region was won by Christendom again the tower was so much associated with the then-previous owners that it was named after them. It should be noted that the tower has many names - "Perušić Fortress" and "Perušić Tower" are two of them.
When I first visited the tower in 1995 its interior was filled with earth up to about two meters, making it look like the hill it stands on was growing through it. Some time since then the earth was dug out, and sometime between 2007 and now the wood ladders and framework was erected inside.