From Diablo Wiki
Checkpoints in Diablo 3 function similar to respawn points in FPS games. Players who die appear back at the last checkpoint they reached, usually at the stairs that they took to reach the current level, or the closest chokepoint that separates two outdoor levels.
Checkpoints are not spots on the ground that must be clicked, like waypoints. They aren't visible in the game at all, until your character passes through one, at which point a "checkpoint reached" title pops with flashing graphics.
Checkpoints are designed to save players time and effort when they die, allowing their character to quickly rejoin the party and continue the battle. Players restart at the last checkpoint they passed through, fully equipped and recovered in health. Checkpoints are common enough that a character seldom requires more than a minute to run from one to the site of their death.
 List of Checkpoints
 Act I
Quest: Fallen Star
- Entrance to Tristram
- Just as you reach Old Tristram Road
- As you enter The Old Ruins
- After returning to Tristram from the Ruins and speaking with Captain Rumford
Quest: The Legacy of Cain
- Approaching Adria's Hut
- Entrance to Cathedral - level 1
- End of Cathedral - Level 1 at entrance to Leoric's Passage
- When Headcleaver is dead
- Handing in quest
Quest: A Shattered Crown
- In Cellar of the Damned - After killing Haedrig's wife, Mira.
- Just outside Tristram at the end of the bridge into The Weeping Hollow.
- Just beyond the gates of the Cemetery of the Forsaken.
- Inside the entrance to the Chancellor's Tomb - Just after you have killed Manglemaw.
- After returning the crown to Haedrig in Tristram.
Quest: Reign of the Black King
- Inside the entrance of the Cathedral, Level 2 from Leoric's Passage.
- Inside the entrance of the Cathedral, Level 3.
- Entranceway to Cathedral, Level 4, after accepting the help of the Templar after killing Jondar.
- Inside the entrance of Cathedral, level 4.
- Inside the entrance of The Royal Crypts.
- Just before entering the Ornate Door to the Crypt of the Skeleton King.
- After killing the Skeleton King.
- Returning to Tristram with the Stranger.
- After speaking with Cain about the Stranger.
Quest: Sword of the Stranger
- End of the bridge from Cemetery of the Forsaken into Fields of Misery.
- Outside entrance to Khazra Den.
- After handing in the sword shard to Deckard Cain.
Quest: The Broken Blade
- As you approach the slope up from Fields of Misery to The Old Mill.
- After activating the Waypoint just before the Drowned Temple after talking to the Scoundrel.
- Just across the bridge that Alaric raises for you from the Drowned Temple to The Festering Woods.
- Just inside the entrance of Warrior's Rest and Crypt of the Ancients.
- Just back across the bridge from The Festering Woods to the Drowned Temple once you have collected the Beacons.
- After entering the Drowned Temple.
- After killing the unique brothers in the Drowned Temple.
- After returning to Tristram with the sword shard.
Quest: The Doom in Wortham
- As soon as you land in Wortham.
- After killing Urzel Mordreg outside the Wortham Chapel.
- After returning to Tristram through the Wortham Waypoint.
- After the cutscene at the end of the quest.
Quest: Trailing the Coven
- Just outside, and just inside, the entrance of the Caverns of Araneae.
- As you approach the Chamber of Queen Araneae.
- After leaving the Chamber going in to the Highlands Crossing.
- Once you have found Karyna's Lost Wagon.
- Once you've opened the Khazra Barricade.
- As your approach Leoric's Hunting Grounds in the Northern Highlands.
- At the Iron Gates to Leoric's Manor Courtyard.
- After you've killed Maghda's minions in the Manor.
Quest: The Imprisoned Angel
- Just as you enter the Halls of Agony
- Just as you go down to Level 2 of the Halls
- When you reach the Highlands Passage
- After speaking with Queen Asylla in The Cursed Hold
- As you approach the Chamber of Suffering entrance on level 3 of Halls of Agony
- After killing the Butcher and approaching the Cells of the Condemned
Quest: Return to New Tristram
- As you return to New Tristram to talk to Tyrael
 Act II
Quest: Shadows in the Desert
- Just as you step into the Hidden Camp
- Just outside the Caldeum Bazaar into the Sundered Canyon
- As you reach the pile of rocks blocking the canyon
- As you step into the Secret Altar in the Howling Plateau
- After you break the ritual in the Secret Altar
- As you step into the Hidden Conclave in the Howling Plateau
- After you break the ritual in the Hidden Conclave
- As the Enchantress reveals the Black Canyon Bridge
Quest The Road to Alcarnus
- Just across the Black Canyon Bridge
- As you reach the Khasim Outpost
- Once you have killed the Decievers in the Outpost
Quest City of Blood