woman walking on green grass field

Istria 100 by UTMB 42K

42K·Istria
ultra100 mile100k50kmountainforesttechnicaltrailcoastalqualifier

Photo by Massimo Sartirana on Unsplash

Distance42K
Date10 Apr 2026

Registration is closed for Istria 100 by UTMB 42K

Get alerted if spots open up or when next year's registration goes live.

About This Race

The 42K strikes the perfect balance at Istria 100, offering runners a full marathon experience across the peninsula's most representative terrain without the multi-day commitment of the longer distances. This distance captures the complete Istrian trail experience—technical descents through ancient forests, stream crossings, and passages through medieval towns—while remaining accessible to runners stepping up from road marathons or shorter trail races. The course demands respect for its technical sections and elevation changes, but rewards runners with a comprehensive tour of the region's diverse landscapes in a single, challenging day on the trails.

Practical Info

Weather

Spring conditions with potential temperature swings from 0°C at night in mountain areas to over 25°C during the day. Sudden weather changes including rain, hail, and fog are possible.

Nearest Airport

PUY - Pula Airport

Required Gear
  • mobile phone with international roaming
  • mandatory safety equipment per UTMB standards

Best For

experienced trail runnersultrarunnersinternational travelers

Notable Features

Part of the prestigious UTMB World Series, this event uniquely combines challenging mountain terrain with coastal elements and cultural immersion through medieval Istrian towns. The courses feature technical single track, stream crossings, canyon passages, and elements of coasteering, making it one of the most diverse trail running experiences in Europe.