3 Day Mega Event - Collectors 15 and Under Are FREE - Friday 4pm - 9pm | Saturday 10am - 6pm | Sunday 10am - 4pm If you're looking for a one-of-a-kind event that celebrates the joys of card collecting, your search is over. The Union Marketplace is the only event of its kind on the west coast, and it's this March in sunny San Diego. This is your chance to meet other collectors, hobbyists, and anyone who just wants to have a great time. You'll find everything you're looking for at The Union Marketplace in Del Mar. Remember that collectors 15 and under are always free - bring the kids!