Romans in Tucson? The Mystery of the Silverbell Artifacts, an exhibit of archaeological finds that some say may indicate the existence of a first-century Roman settlement in Tucson, continues through the fall. Several of the artifacts were featured in an episode of the H2 Channel's America Unearthed. Mapping the Territory, an exhibit covering the decade from the Gadsden Purchase in 1853 to President Abraham Lincoln's signing of the Arizona Organic Act in 1863, continues through Tuesday, Dec. 31. Hours are 10 a.m. to 4 p.m., Monday through Saturday; $5, $4 seniors and youth ages 12 through 18, free for members and younger children.