'Tower' in the Bible

'Hear ye another simile: There was a certain man, a householder, who planted a vineyard, and did put a hedge round it, and digged in it a wine-press, and built a tower, and gave it out to husbandmen, and went abroad.

And he began to speak to them in similes: 'A man planted a vineyard, and put a hedge around, and digged an under-wine-vat, and built a tower, and gave it out to husbandmen, and went abroad;

'Or those eighteen, on whom the tower in Siloam fell, and killed them; think ye that these became debtors beyond all men who are dwelling in Jerusalem?

'For who of you, willing to build a tower, doth not first, having sat down, count the expence, whether he have the things for completing?