Thung Setthi Fortress is situated south of Nakhon Chum, on the east bank of the Ping River, along Phaholyothin Road, near several ancient temples, including Wat Nong Phikul, Wat Sum Ko, and Wat Nong Langka. The fortress was part of the Nakhon Chum city defense system, a twin city of ancient Kamphaeng Phet.

Architecture:
The fortress was built from strong laterite, forming a square structure 83.5 meters wide and about 6 meters high. It has main gates at all four sides, wide battlements for movement, and interconnected chambers under the walls. Each corner has a projecting bastion with a ground-level observation hole. The walls feature sema stone decorations. Today, the north side has been partially removed, leaving three sides, but the overall structure remains solid, reflecting Western architectural influences introduced in mid-Ayutthaya period.

Historical Significance:
Thung Setthi Fortress played an important defensive role in Nakhon Chum during the mid-Ayutthaya period. It is also a site where famous amulets of Kamphaeng Phet were discovered, including Phra Sum Ko, Lila Med Khun, Thung Setthi, and Kamphaeng Kheang, representing the artistic and spiritual beliefs of the past. This makes the fortress valuable in terms of architecture and ancient artifacts.

Current Condition and Preservation:
The fortress remains structurally strong and clearly defined, even though the north side was removed. It is maintained by the Fine Arts Department and Kamphaeng Phet Historical Park to preserve it for tourists and educational purposes.

Connection to Nearby Historical Sites:
Visitors can explore the fortress together with nearby ancient temples such as Wat Nong Phikul, Wat Sum Ko, and Wat Nong Langka for a comprehensive historical experience of Nakhon Chum.

Heritage Status:
The Fine Arts Department designated it as a historical site in 1962 (B.E. 2505), and Thung Setthi Fortress is part of the Kamphaeng Phet Historical Park, which is a UNESCO World Heritage site.

By Car:

• From Kamphaeng Phet city, take Phitsanulok/Main Road to Highway 101 (Kamphaeng Phet–Sukhothai)

• Drive about 5–6 km until reaching the Ping River, then cross the bridge to the west bank into Nakhon Chum Subdistrict

• Thung Setthi Fortress is along Phaholyothin Road, clearly visible from the street

By Motorcycle:

• Follow the same route as by car. Park near the fortress roadside or use nearby temple parking, e.g., Wat Nong Phikul

By Public Transport:

• From Kamphaeng Phet city, take a songthaew or minivan to Nakhon Chum

• Get off at Phaholyothin Road in front of Thung Setthi Fortress, then walk to the site

• Explore Around the Fortress: Walk around all sides to observe the battlements and chambers up close.

• Visit Nearby Temples: Combine your visit with Wat Nong Phikul, Wat Sum Ko, and Wat Nong Langka for a full-day historical tour.

• Best Time to Visit: Plan to visit before 5:00 PM.

• Gear and Safety: Wear suitable shoes, hat, bring water and umbrella; watch out for uneven or damaged ground.

• Photography: Best spots are wall corners and ground-level observation holes, especially in the evening for natural light.

Admission Fee:

• Free of charge (no separate fee from Kamphaeng Phet Historical Park)

Opening Hours:

• 9:00 AM – 5:00 PM (may change; check with Kamphaeng Phet Historical Park before visiting)