'Watchtower' in the Bible

"Listen to another parable. There was a landowner who planted a vineyard, put a wall around it, dug a wine press in it, and built a watchtower. Then he leased it to tenant farmers and went abroad.

Then Jesus began to speak to them in parables. "A man planted a vineyard. He put a wall around it, dug a pit for the wine press, and built a watchtower. Then he leased it to tenant farmers and went abroad.