Skip to content
Run SEA

Bangsaen21

Bangsaen21 is a half-marathon (21.1 km) held at Bang Saen Beach in Bangsaen, Chonburi, Thailand on December 20, 2026.

Compiled by the Run SEA editorial team from the sources cited below — not a first-hand race report. How we research listings.

Facts last checked August 25, 2026

Bangsaen21 is a half-marathon scheduled for December 20, 2026, taking place at Bang Saen Beach in Bangsaen, Chonburi, Thailand. The event covers the standard half-marathon distance of 21.1 km. Registration details have not yet been announced. This event carries a verified tag, indicating its details have been confirmed as accurate.

The bottom line

Bangsaen21 is a companion event to the Bangsaen42 Marathon covered elsewhere in this research batch -- same beach, same folklore-rich name origin, but a single-distance 21.098K half marathon rather than the full marathon/10K/half spread offered five weeks earlier. Together, the two races give Bang Saen Beach -- Thailand's first government-built holiday resort, dating to 1943 -- essentially two distinct running events across the December period. Registration status wasn't yet announced at the time of this research.

Key facts
Date2026-12-20
Distance Km21.098
Primary Distance Km21.1
VenueBang Saen Beach
CityBangsaen, Chonburi
CountryThailand

A Second Race at the Same Historic Beach

Bangsaen21 offers a single distance: the 21.098K half marathon, at Bang Saen Beach, Chonburi. [1] This is a separate event from the Bangsaen42 Marathon covered elsewhere in this research batch, which offers 10K/21.1K/42K roughly five weeks earlier -- together the two races give Bang Saen essentially two distinct running events spanning the November-December period.

Thailand's First Purpose-Built Resort

Bang Saen Beach was the site of the Thai government's first purpose-built holiday resort, constructed in 1943. [2] The beach's name traces to local folklore about two tragic young Chonburi lovers, Saen and Sam Muk, whose story is woven into several nearby landmark names -- the same heritage detail covered at the Bangsaen42 review elsewhere in this research.

A Half-Marathon-Only Format

Unlike Bangsaen42's three-distance spread, this event offers just the half marathon -- a more focused format similar to Selangor Marathon's marathon/half-only approach covered elsewhere in this research. [1] That narrower focus suggests an event aimed at committed half-marathon runners specifically, rather than a broader multi-distance community race.

Registration Not Yet Announced

As of this writing, registration status has not been announced. [1] Given Bang Saen's proximity to both Bangkok and Pattaya, and the beach's genuine historical significance, demand could be reasonably strong once details firm up.

Should You Run It?

If you want a focused half marathon at Thailand's historically significant first holiday resort -- especially if you're pairing it with or choosing it over the earlier Bangsaen42 full marathon -- Bangsaen21 on 20 December 2026 is a solid, single-distance pick. Watch official channels for registration to open.

References & sources

  1. 1. Bangsaen21 2026 — official site — bangsaen21.com
  2. 2. Bang Saen Beach — Wikipedia — Wikipedia

Quotes are short excerpts reproduced under fair use and attributed to their original authors; follow the links above for the full context. This article is an independent summary and is not affiliated with the event.

Pros

  • Scenic beachfront venue at Bang Saen Beach
  • Standard half-marathon distance of 21.1 km
  • Listed as a verified event
half-marathon thailand verified

Find out more about Bangsaen21

Frequently asked questions

When is Bangsaen21 taking place?

Bangsaen21 is scheduled to take place on December 20, 2026. The event will be held at Bang Saen Beach in Bangsaen, Chonburi, Thailand, offering participants a half-marathon race experience along the coastal setting on that specific date.

What distance is Bangsaen21?

Bangsaen21 is a half-marathon event with a primary distance of 21.1 km, which corresponds to the standard 21.098 km half-marathon length. This makes it suitable for runners looking to complete a classic half-marathon distance.

Where is Bangsaen21 held?

The race is held at Bang Saen Beach, located in Bangsaen, Chonburi, Thailand. This beachfront venue serves as the setting for the half-marathon event scheduled to take place on December 20, 2026.

Can I register for Bangsaen21 now?

According to available information. Prospective participants should check back later for updates on when and how registration will open for this half-marathon event in Thailand.

Is this the same as the Bangsaen42 Marathon?

No -- they're separate events at the same beach roughly five weeks apart. Bangsaen21 offers only the 21.098K half marathon on 20 December 2026, while Bangsaen42 offers 10K/21.1K/42K distances earlier, on 15 November 2026. [1]

Why is Bang Saen historically significant?

The Thai government built its first purpose-built holiday resort there in 1943. The beach's name comes from local folklore about two tragic young Chonburi lovers, whose story is tied to several nearby landmark names. [2]

Related races

22NOV
RUN FOR FREEDOM – Bitcoin Thailand Half Marathon

Chiang Mai, Thailand

Half Marathon (21.1km) 10K 5K
1NOV
Scenic Half Marathon Chiang Mai (CMSH)

Chiang Mai, Thailand

Half Marathon (21.1km) 10K 5K
13SEP
Scenic Half Marathon Krabi 2026

Ao Nang, Krabi, Thailand

Half Marathon (21.1km)
6SEP
Watlaharnrai Half Marathon (5th ed.)

Ban Khai, Rayong, Thailand

Half Marathon (21.4km) 10K 5K
25OCT
Mae Moh Half Marathon

Mae Moh, Lampang, Thailand

Half Marathon (21.1km) 10K 5K
20DEC
Bangkok Midnight Marathon 2026

Bangkok, Thailand

Half Marathon (21.1km) 10K