Puerta de Alcalá
This triumphal arch, a popular backdrop for photos, was built by Carlos III in 1778 to mark the site of one of the ancient city gates. You can still see numerous bullet and cannonball holes on its exterior, left intentionally as a reminder of Madrid's tumultuous past. Conservationists are thrilled that the €3 million, 11-month restoration ending in 2024 "saved" the structure, which was beginning to crumble due to pollution and structural issues.