Minecraft wiki entry for Nether_survival, associated text: Lava is plentiful in the Nether, in huge lakes (a sea of lava is near the bottom) rivers, and falling from the ceiling. You must be careful around lava as water buckets do not work in the Nether, and ice disappears instead of melting into water. Also, lava spreads much faster and farther in the Nether than in the Overworld (7 blocks instead of 3). Two good ways of crossing lava are to make a potion of Fire Resistance or eat an enchanted golden apple; while this effect is active, you can swim through lava without taking damage. Fire Protection on your armor can also protect you from lava: if using iron armor or better with the maximum possible protection, you take only half a heart of damage every couple seconds (with higher tier armor reducing how often you take damage), which is small enough that it can be outpaced by the natural regeneration you receive from a full hunger bar. This level can be achieved by wearing 1 armor piece with Fire Protection IV and 3 with Protection IV, or by wearing 2 armor pieces with Fire Protection IV and 1 with Protection IV. Note, however, that this rapidly damages your armor's durability. This can be mitigated with the Unbreaking and/or Mending enchantments, or completely negated by using Netherite armor, which doesn't lose any durability from fire and lava damage. It also uses up food as you'll need to keep eating in order to keep healing, so it's not as suitable as a Fire Resistance potion for crossing large bodies of lava, but it does remove the danger of dying from accidentally falling into lava without having to constantly drink potions "just in case." Fire Protection also has the side benefit of reducing the amount of time it takes for you to stop burning if you catch on fire from the lava. If any lava is in the way of your builds, simply clear it out using a bucket or fill it with blocks, and then continue on.