Great Gate of Minas Tirith
From Tolkien Gateway
The Great Gate was the mighty gate of Minas Tirith, capital city of Gondor, leading from the lowest of its seven tiers out onto the Pelennor Fields.
It was destroyed by Grond during the Battle of Pelennor Fields. After the War of the Ring, the Dwarves of Aglarond built a new one of mithril.