The City of Santo Domingo City*1

Santo Domingo City is a the capital from of The Dominican Republic.*2 It's a beautiful city.*3
Santo Domingo City has the Colonial Zone. In the Colonial Zone, you can see a lot of buildings and a lot of tourists from a lot of different country countries. I love my city.

*1

It sounds more natural to say "the city of Santo Domoingo" instead of Santo Domingo city. 

*2

THE capital = because there is only ONE capital in a country.

A capital = this would imply there is more than one capital in a country, so it is incorrect.

*3

It is = It's

Its = shows posession. My shirt. His shirt. Its shirt. 

Santo Domingo City

Santo Domingo City is the capital of Dominican Republic. It's a beautiful city.
Santo Domingo City has a colonial zone. In the colonial zone you can see a lot of buildings. A lot of tourists from different countries visit it. I love my city.