The International Modern Pentathlon Union (UIPM) has selected obstacle discipline as the replacement for riding, which has been controversially axed from the sport.

Athletes at the event in the Turkish capital, scheduled for June 27 and 28 after the Pentathlon World Cup Final, will face challenges such a "tsunami" curved wall at the finish.

They must also contend with a rope swing, monkey bars, angled ladders and a balance beam on a course designed in collaboration with World Obstacle.

A 1.5 metres wall, offset steps, a 0.5m low crawl, a rings rig, a wheels rig and an "under-over-under-over" section are other parts of the course.

Adding obstacle discipline has been described by the UIPM as the "biggest shake-up of the Olympic sport in its 110-year history".

If approved at this year's UIPM Congress, it would replace riding after the Paris 2024 Olympics as the sport bids to keep its spot for Los Angeles 2028.

Modern pentathlon has been left off the initial programme for the Californian Games, and International Olympic Committee (IOC) President Thomas Bach has warned that the proposal for riding's replacement, and the overall competition format, must be finalised before it can be included.

"Athletes have been invited to run, walk, climb, crawl, slither, scramble or otherwise propel themselves to the finish line of a bespoke course in Ankara," the UIPM said.

Two to four athletes will race each other over the course, which will be up to 100m long, at one time.

There will be separate categories for under-19, junior and senior pentathletes in Ankara - and another for experienced obstacle discipline competitors.

The UIPM has claimed that obstacle athletes now have a route to the Olympic Games, if they are able to add swimming, fencing and laser-run skills to their repertoire. 

It said obstacle discipline would make the sport, initially created by Olympic founder Pierre de Coubertin, "more exciting to watch and more globally accessible, popular and sustainable".

Riding was dropped from modern pentathlon after controversy at the Tokyo 2020 Olympics last year, when German coach Kim Raisner was sent home in disgrace for punching a horse during the women's competition.

Horses are designated to pentathletes at random, which can lead to unpredictable behaviour and is deemed by some to be unfair.

The UIPM's Fifth Discipline Working Group eventually settled on obstacle as its replacement, and claimed it followed 13 established criteria before reaching its decision from more than 60 possible sports.

But its work has been heavily criticised, particularly by the Pentathlon United group which has hit out at riding's removal while alleging a lack of transparency in the process to replace it.

The group has asked the IOC to investigate the UIPM's governance after claiming a "heavy-handed and unconstitutional manner in which the UIPM acted to remove the equestrian discipline".

More than 93 per cent of respondents to a Pentathlon United survey are reportedly "unhappy with the direction the sport is going in".

Access to the test event in Ankara has been requested by the group.

UIPM President Klaus Schormannm, who has led the body since 1993, chaired the Fifth Discipline Working Group himself.

World Obstacle has said it is happy to work with the UIPM on incorporating the discipline.