In total there are nine Challenge Tombs in the main campaign and completing them ALL will unlock the 'Tomb Raider' Trophy. None of the Challenge Tombs are missable and each of them can be done after the story in free-roam. No special gadget is required for any of them and they can be attempted as soon as you reach their respective area through story progression. Your objective is to reach the stele (small statue) at the end of the tombs. Each of the Challenge Tombs unlocks a new skill, getting them ALL in one category will unlock the 'Specialized' trophy.
#1 - Peruvian Jungle (Underworld Gate) - 0:11
#2 - Peruvian Jungle (Judge's Gaze) - 7:17
#3 - Kuwaq Yaku (Howling Caves) - 13:12
#4 - The Hidden City (Path of Battle) - 19:59
#5 - The Hidden City (Temple of the Sun) - 27:21
#6 - The Hidden City (Ancient Aqueduct) - 36:28
#7 - Cenote (San Cordoba) - 45:08
#8 - Mission of San Juan (Tree of Life) - 53:29
#9 - Mission of San Juan (Thirsty Gods) - 1:03:56