Miradors are small rooms at a tower located at the highest floor of the house and used as a lookout. You have seen this before, especially in older houses. It’s usually topped by a weather vane, and marked with a letter O, which stands for ‘oeste,’ Spanish for west.
The mirador is an element in older architecture tracing back to the earlier days when castles had turrets or lookout towers (the word mirador literally means turret or tower). The higher vantage point allowed sentries to strategically defend their castles and protect its inhabitants.
Eventually, this element became less related to wars and sieges but as reminiscent of Spanish architectural influence. Turrets were traditionally supported by a corbel.
The mirador is an element that is common in most Spanish style houses. However, not all Bahay na Bato have these towers.
Reference:
“Turrets in Architecture: Definition, Design & Construction”. https://study.com/academy/lesson/turrets-in-architecture-definition-design-construction.html
Martinez, Glenn. 2018. “Here’s A Complete List Of The 46 Parts of A Filipino House.” www.realliving.com.ph. May 26, 2020.