Iran is set to host its first international marathon race in the capital of Tehran next week, and will include dozens of runners from countries like the United States and the United Kingdom.

Organizers say the landmark sporting event is “to show everybody that Iran is a partner in making bridges, not walls.”

The marathon will be a major logistical feat for the bustling city, which is currently home to 16 million residents. The considerable congestion from the thousands of vehicles that clog the streets on a daily basis also contribute to significant levels of air pollution, which has reportedly killed hundreds of people in the past.

The race will be held on a Saturday in an attempt to lessen the impact on the huge city.

The race will also be the first marathon held in Iran to formally allow females to compete. Last year, Iran’s first organized marathon officially forbade women from participating, although two women ran anyway as a form of protest.

Female participants will still be required to adhere to a strict dress code. “Women are obliged to wear a headscarf or sports bandana (so that your hair will be covered). A T-shirt with long sleeves and a running pants can be a good choice. Please keep in mind that the length of the T-shirt can not be too short (T-shirt must cover your hips). You may not wear shorts or skirts showing  bare legs.”

The “I run Iran” annual marathon is a government-sanctioned sporting event that is “part of a campaign to run for fun aimed at young Iranians,” according to the race’s website.

Iran has a massive youth population, with over 60 percent of the country’s 80 million citizens made up of people under the age of 30.