The address to save
मंगलनाथ मंदिर, सांदीपनि आश्रम के पास, मंगलनाथ रोड, उज्जैन शहर, उज्जैन, मध्य प्रदेश 456006. That is the line to keep in the phone. The temple is on the river side of Mangalnath Road, quieter than the lanes around Mahakaleshwar and still a working temple road.
A booked Mangalnath Mandir Bhat Pooja is not the same as arriving for darshan. Darshan does not reserve the sankalp. Message before you travel so someone is expecting the name.
From Mahakaleshwar
The mandir is commonly described as about 6 km from Mahakaleshwar. It is a short ride, not a walk between the two shrines. Autos and taxis know the road. On a festival morning, leave earlier than the map suggests. The last stretch fills with people coming for darshan.
If your hotel is near the Mahakal corridor, the same instruction holds: Sandipani Ashram, Mangalnath Mandir. Do not ask only for “the Mars temple” in English and hope. The Hindi place names are the ones drivers use.
From Ujjain Junction
From the railway station, take an auto or a taxi and use the same two names. There is no need for a tour package to cover this ride. If you are also going to Mahakaleshwar the same day, do the booked puja first, at the muhurat, and the corridor after. Reversing that order is how families miss the sankalp.
Parking is usually in front of the temple. On holidays it is tight. An early muhurat is the calmer arrival.
When you are at the gate
You are looking for the pandit who has your name, not a general queue for darshan. Keep the WhatsApp confirmation on the phone. The phone numbers on this site are +91 98273 13905 and +91 9343 877365. If the lane is confusing, call from the auto rather than wandering the ghat.
Wear simple traditional clothes. The vidhi is about an hour for the core bhat offering. Plan the rest of Ujjain after it, not during it.