Wichaiprasit Fort, also known as Wichaieng Fort, is located along the west bank of the Chao Phraya River, north of the mouth of Khlong Bang Luang (Khlong Bangkok Yai). It currently lies within the Royal Thai Navy Headquarters area on Arun Amarin Road, Bangkok Yai District, Bangkok.

Originally a fortress at the corner of Bangkok’s old city walls (Thonburi), it was constructed during the Ayutthaya period to protect the river mouth — a vital trade route. It is believed to have been built before the reign of King Narai the Great, possibly with Portuguese design assistance. During King Narai’s reign, the fort was renovated and the city’s defenses rebuilt, potentially under the orders of Chaophraya Wichai Yont (Constantine Falco).

The fort’s design and construction were overseen by Monsieur de la Mare, a French engineer responsible for several fortresses during King Narai’s era, with technical advice from Father Tomaso Valguarnera, an Italian Jesuit priest. La Mare planned star forts on both riverbanks with chains stretched across the river to block ships, though only the eastern fort was completed before political upheaval near the end of King Narai’s reign. The eastern fort was later demolished in the Rattanakosin era (some sources say during King Phetracha’s reign).

Wichaiprasit Fort retains its original structure. Some sources call the eastern fort Wichaieng Fort and the western fort Wichaiprasit Fort, while others refer to both collectively as Wichaieng or Bangkok Fort. When King Taksin established Thonburi as the capital, he built a palace near the western fort and renamed it Wichaiprasit Fort.

• Bus routes 3, 6, 9

• Chao Phraya Express Boat, get off at Wat Arun Pier

• Taxi or motorcycle taxi

• Visit in the early morning or late afternoon to avoid midday heat

• Wear comfortable shoes for walking around the fort

• Bring a camera to capture riverside views and architecture

• Try local street food nearby after touring

• Check weather and transportation options before visiting

Admission Fee:

• Thai visitors: Adult 20 THB, Child 10 THB

• Foreign visitors: Adult 100 THB, Child 50 THB

• (Updated 2025 by the Fine Arts Department)

Opening Hours:

• Open daily 09:00 – 17:00

• (Fort closes promptly at closing time)