Market 23 & Market 28

Market 23 -- Take the R-1 bus (NOT if it says Wal-Mart on it however) from the hotel zone. You will turn right on Tulum Ave. Pass 1 traffic circle & see a large Commercial Mexicana store (after the trafic circle is the bus stop for the bus station). 100 yards later on the right you will pass a McDonald's, then a movie theater then (before the 1st traffic lights) you will come to a small "games area" for children. Get off. Why did the tourist cross the street? To get to Market 23! Cross the street & behind the fire station is the Market.
To get back to the hotel zone...go back to Tulum Ave (same side of the street as the fire station) & get the R-1 again.

Market 28 -- Take any bus that has Wal-Mart on the front window will get you there. For sure the R-2 & R 15. Once downtown, tell the bus driver Market 28. If he lets you off at the correct corner...turn right at that corner/traffic lights & walk straight for 3 blocks & you will walk right into the Market. If the bus driver lets you off at Wal-Mart (which means he passed the corner) walk back 1/2 of a block & turn left.
OR take any bus downtown then take a taxi to either Market for about $1.50 US.