The Red Fort, also known as Lal Qila, is a magnificent example of Mughal architecture located in the heart of Delhi, India. Constructed during the reign of Emperor Shah Jahan in the mid-17th century, this UNESCO World Heritage Site served as the main residence of the Mughal emperors for nearly 200 years.

Architectural Features and Construction:

1. Construction and Dimensions: The construction of the Red Fort began in 1638 and was completed in 1648. The fort spans over 254.67 acres, with massive walls extending up to 2.41 kilometers. The height of the walls varies from 18 meters on the riverfront to 33 meters on the city side.
2. Architectural Style: The Red Fort is a quintessential example of Mughal architecture, combining Persian, Timurid, and Indian architectural styles. The fort’s design incorporates extensive use of red sandstone, hence its name.
3. Key Structures: The fort complex includes several notable structures such as the Diwan-i-Aam (Hall of Public Audience), Diwan-i-Khas (Hall of Private Audience), the Rang Mahal (Palace of Colors), and the Moti Masjid (Pearl Mosque). Each structure showcases intricate carvings, inlaid decorations, and exquisite gardens.
4. Gardens and Water Features: The fort is known for its lush gardens laid out in the Charbagh style, which divides the garden into four parts. The fort also features a sophisticated water supply system with channels running through the palaces, creating a cooling effect and adding to the aesthetic appeal.

Innovations and Engineering Techniques:

1. Fortification: The Red Fort’s fortification includes high walls made of red sandstone, designed to protect against invaders. The walls are punctuated with bastions and turrets for enhanced defense. The Lahore Gate and Delhi Gate are the two main entrances, both adorned with intricate marble inlays and carvings.
2. Architectural Design: The fort’s design exemplifies the zenith of Mughal creativity, with a focus on symmetry and grandeur. The palaces within the fort feature scalloped arches, marble screens (jaalis), and pietra dura inlay work using semi-precious stones.
3. Cooling Systems: The palaces are equipped with ingenious cooling systems, including water channels (Nahr-i-Bihisht) running through the palaces and marble pools, providing relief from the intense heat of Delhi.
4. Construction Materials: Red sandstone and white marble are predominantly used in the fort’s construction, contributing to its majestic appearance. The combination of these materials also allowed for elaborate decorative work, enhancing the overall aesthetic of the structures.

Trivia and Lesser-Known Facts:

• The Red Fort was originally known as “Qila-i-Mubarak,” meaning the Blessed Fort, as it was the residence of the royal family.
• The Koh-i-Noor diamond was once part of the peacock throne, which was housed in the Red Fort.
• The fort served as the main center of the Indian Rebellion of 1857 against British rule. It later became the site where the British formally ended Mughal rule.
• The Prime Minister of India hoists the national flag and delivers a speech from the ramparts of the Red Fort on Independence Day every year.