Centro Cultural Tijuana is a shining star in the center of Tijuana, Mexico. Set among a series of new buildings with geometric shapes (such as ball), the large plaza that connects an art center and museum, gift shop and IMAX theatre, offers a very modern look, contrasting with older surrounding buildings.  Opened in 1982 as a showpiece for the city that includes over 1,800,000 residents, the exhibits and museum collection is world class, and well worth a visit on your next trip to Tijuana. Best of all, it's free.   While our group of Americans wandered in a guided tour, we began to see the world through Mexico's eyes for a change. Suddenly aware that the 21 California missions didn't just stop at the border, Baja California's missions were represented in small models. A beautiful collection of masks, carved wooden figures, including a striking 400-year old  crucifix, authentic pieces and replicas of other items all provided a visual display that doesn't require knowledge of any particular language to enjoy. Rotating, themed photo exhibits, art and educational displays are mounted on colorful exhibit walls, making for a  more interesting approach to learning.   A  popular complex for school kids, we wandered into the IMAX theatre where the children were watching a stunning video about nature. Having just visited a display on masks and the role they play in Mexican culture, it helped to shed light on the audience's delight when a scary-looking warrior with a painted face appeared larger than life on the screen. While kids in an American school would possibly be frightened by the ominous noise and threatening character, these pre-teens were howling with laughter. Something as simple as a show and the audience response offers a glimpse into cultural differences.   The Mexico Centro Cultural Tijuana doesn't cost a dime to visit, and helps shed light on many customs and cultures that make up this vast and amazing country.  Centro Cultural Tijuana is located at Paseo de los Heroes 9350, Zona Urbana Rio, Tijuana, (664) 678 96 00 Grand Hotel Tijuana is located at Blvd. Agua Caliente 4500 Col. Aviacion, (664) 681 70 00   Tijuana Convention and Visitors Bureau tel: (011 52 664) 684 0537. tijuanaonline.org.  They know their stuff and really helped me