Wadi Mujib is in King's Highway of Jordan, to the east of the Dead Sea. It's a popular site for canyoning.
Be sure to put the activity centre into any route planner, as Google maps will take you to the other end of the Wadi which is about 20 km away from the entrance.
The activity centre is around 1 hr 20 min from Amman by car. Public transport options are fairly limited so if you don't have a car the best option might be to hire a taxi. In low season it is possible to hire a taxi from Amman with some haggling for 50 JD (as of Sep 2022) including sufficient waiting time at Wadi Mujib and the Dead Sea (there's a free public beach around 500 m south of the activity centre). Ride-hailing apps Careem and Uber are also options for getting there; prices from 20 JD one way (September 2022), but getting a lift back may prove more of an issue. It is useful to show the taxi driver the quote from Careem when negotiating a price.
Entrance is controlled by a private company, for the basic trail (with no guide) it costs 21 JD (as of Sep 2022) per person, and includes life jacket rental only. Water shoes are available to rent as are dry bags although the latter costs 10 JD (cash only) although you shouldn't count on them keeping your things dry. As of Sep 2022, there are no lockers or other storage facility's available.
The number of people allowed in is limited so depending on the time for the day, you may have to wait to buy your ticket. This can take over an hour, so most recommend going early.
The main trail is usually only open for 3 months a year depending on water levels, so might be useful to call ahead.
There is a café on site, but it was closed as of Sep 2022, so it's a good idea to bring your own food and water. There are no shops within walking distance.
There are no helmets provided.