In this guide I am gonna tell you how to get the well known There and back again achievement.
there are 72 places in total you need to visit in order to unlock this achievement.

ACT 1 -18 Total locations
ACT 2 -27 Total locations
ACT 3 -12 Total locations
ACT 4 -15 Total locations

There are a total of 18 places you need to visit in ACT 1

Act1_Zone_DiamondBeach
Act1_Zone_DiamondDistrict
Act1_Zone_GasStationLighthouse
Act1_Zone_GoldenBeach
Act1_Zone_GoldenDistrict
Act1_Zone_Hotel
Act1_Zone_HotelBungalows
Act1_Zone_GasStationTunnel
Act1_Zone_SilverDistrict
Parking_Zone_ServerRoom
Parking_Zone_Ambulatory
Parking_Zone_Pool
Parking_Zone_OfficeLobby
Parking_Zone_ControlRoom
Parking_Zone_ParkingGroundZero
Parking_Zone_Kitchen
Act1_Zone_OldMarina
Act1_Zone_OldMarinaWorkshop

There are a total of 27 places you need to visit in ACT 2

Act2A_Zone_CanaleStreet
Act2A_Zone_Graveyard
Act2A_Zone_Church
Act2A_Zone_DeadZone
Act2A_Zone_DownTown
Act2A_Zone_EasternWaterfront
*Act2A_Zone_GasStation
Act2A_Zone_GasStation
Act2A_Zone_MarketDistrict
Act2A_Zone_NicksHub
Act2A_Zone_OldTown
Act2A_Zone_OldtownBridge
Act2A_Zone_PoliceStation
Act2A_Zone_Riverside
Act2A_Zone_ShantyTown
Act2A_Zone_SimonsHub
Act2A_Zone_VictoryHill
Act2A_Zone_Warehouses
Act2A_Zone_WastewaterPlant
Act2A_Zone_WaterfrontHarbour
Act2A_Zone_WesternWaterfront
Act2A_PumpFactory_Name
Act2B_Zone_TownSquare
PoliceStation_Zone_Station
PoliceStation_Zone_Parking
PoliceStation_Zone_DetectivesOffice
PoliceStation_Zone_ChiefOffice

There are a total of 12 Places you need to visit in ACT 3:

Act3A_Zone_GaiaFalls
Act3A_Zone_Mowen
Act3A_Zone_SmugglersMarina
Act3A_Zone_GhostTown
Act3A_Zone_JungleVillage
Act3A_Zone_OverpassCamp
Act3A_Zone_RiverVillage
Act3A_Zone_SmugglersCamp
Act3A_Zone_Waterfall
Act3B_Zone_Laboratory
Act3B_Zone_LabWorkshop
Act3B_Zone_NativesCamp

There are a total of 15 places you need to visit in ACT 4

Act4B_Zone_Basement
Act4B_Zone_CB0Armory
Act4B_Zone_CB0Canteen
Act4B_Zone_CB0Enternance
Act4B_Zone_CB0FirstFloor
Act4B_Zone_CB0Kitchen
Act4B_Zone_CB0SecondFloor
Act4B_Zone_CB0Warehouse
Act4B_Zone_CBA
Act4B_Zone_CBB
Act4B_Zone_CBBControlRoom
Act4B_Zone_CBC
Act4B_Zone_CBCMainRoom
Act4B_Zone_Hospital
Act4B_Zone_Sewers

NOTE: ACT 4 starts at a point of no return so make sure you have 57 places unlocked when leaving to the prison, you can check you amount of unlocked places in the menu>extras>achievements>There and back again.
i HIGHLY RECOMMEND GOING BACK IF YOU HAVE 56 PLACES, unless you wanna play the game 5 times ;)

Alot of people have the problem of having 71 unlocked places, there are a couple suggestions you might want to look again:

1. in chapter 15 when you arrive at morsby with mowen to get fuel you can go to the bottom right corner, there is a small bandit camp. most people forget that one.(i recommend checking out the gun store as well, nice loot sometimes and a mod.)

2. you can also forget a place in the Hotel and since its a place you cant go back again make sure you have everything there, i recommend checking the amount of unlocked places before entering the Hotel and when you are at the point of leaving the hotel with the truckl. if you have +7 locations youre good to go:

Parking_Zone_Server Room
Parking_Zone_Ambulatory
Parking_Zone_Pool
Parking_Zone_Office Lobby
Parking_Zone_Control Room
Parking_Zone_Parking Ground Zero
Parking_Zone_Kitchen