which Mayan Site in Belize ?

Hello Yves,
Stop in Orange Walk and take the trip to Lamanai. I recommend Jungle River tours. $40 US gets you a 7 hour tour including the trip up the river, the ruins site with a guide and a hot lunch at Lamanai. It leaves about 9:30AM and returns at 4:30.

I'd recommend Lamanai and Caracol.

There is no public transportation directly to the Lamanai site, but public buses (running between Belize City and Corozal) can drop you off on the highway where the tour boats wait -- just tell the driver or conductor where you want off. Most tours begin around 9 or 10 am and start with a trip along the river to get to the site.

Altun Ha is a small site. Buses run infrequently to villages near Altun Ha, and then you'd need a taxi to complete the trip. Tours are an option.

For Caracol, Xunantunich and Cahal Pech, I'd suggest staying in San Ignacio because the town has a good selection of accommodation for all budgets.

There is no public transportation to Caracol. Visit the tour companies in San Ignacio and join a tour. Also visit the Cayo Welcome Centre for tourist information.

You can get to Xunantunich by bus/foot. Get a bus from SI to Benque and ask to be dropped off at the turn-off to Xunantunich -- that should cost you BZ$1 or $2. After crossing the river on the small ferry, walk the 1 or 2 km to the site. A few hours is all you need here. After walking back to the highway, wave you arm up & down at an approaching bus to get it to stop.

From the centre of San Ignacio, you can easily walk to Cahal Pech.

Another vote for Lamanai and Caracol, both of which are very large and in beautiful settings. Tours to both sites are easy to set up (in Orange Walk and San Ignacio, respectively) and not terribly expensive.

Xunantunich, just off the road between San Ignacio and the Guatemalan border, is worth a look as well. It's small so it's easily done en route between San Ignacio and Tikal.

Thank you very much everybody for your answer ! It helps a lot !
I have another question : is Belize City woth a stay ? Or is it better to go directly (if possible) from Orange Walk to San Ignacio ?

TIA

I wouldn't suggest staying in Belize City or OW Town. You should be able to get to SI after Lamanai.

Belize city is not worth visiting. If you absolutely have to stay, there are a few decent hotels, but there's no there there. Skip it.

Thanks a lot for all the information !