We will be staying at the JW Marriott in Cancun. How long will it take to drive to the ruins at Tulum and is it worth the drive? Are there any ruins closer then Tulum?

If I recall correctly it will take you about 90 minutes to get to Tulum fom Cancun. Whether or not it's worth the drive depends on what YOU expect. There are some interesting ruins and a nice beach. It's not nearly as large or impressive as Chitzen-Itza (sp?) but you can stop at other nearby attractions and make a full day of it if you want.

You can find pictures of Chichen and Tulum ruins in this link..

http://community.webshots.com/user/lamexicana100

Chichen Itza it's about 125 miles from Cancun, and there's two roads, toll road, and the federal ( not recommended, many speed bumpers). The federal road to Tulum it's very safe and easy to drive (80 miles). The site is surrounded by a wall on three sides and has the Caribbean on its eastern flank; a tiny bay lies at the foot of the cliff.

I forgot to tell you, also there's an arqueological site in Cancun, EL Rey. Just a few minutes from your hotel.
This page it's in spanish, you can use a web translator:

http://www.inah.gob.mx/zoar/htme/za02003.html

I would rent a car and get an early start in the morning, trying to hit Tulum before too many hordes of tourist buses hit it, then head inland to Coba -- which is a *BIG* site (but rustic).

Cancun to Tulum: 90 minutes+
Tulum to Coba: 45 minutes+
Coba back to Cancun: 1 hour 20 minutes +/-

Ruins that are closer than Tulum aren't as interesting nor as cool.

Have fun!
Mark
www.tiogringo.com

Great advice from TioGringo. I really enjoy the ruins at Coba and they aren't overrun with tourists like Tulum and Chichen. As he says, go early--otherwise Tulum will be overrun with tour buses.