What you seek lies in front of you. As does what you fear.
In order to retrieve the orange Soul Stone, Thanos and Gamora visit the planet of Vormir, which extracts a high price for the ability to gain the stone.
According to Cinefex #159, background plates were shot at some”sand dunes in Brazil.” This brief led to looking at the most famous sand dunes in the country, at the Lençóis Maranhenses National Park.
(Avengers: Infinity War, 2018)