To make a Nether Portal in Minecraft, you can follow these detailed steps:

### Step 1: Gather Materials
– Obsidian: You can find obsidian naturally or create it by pouring water over a lava source block.
– Water Bucket: Needed for creating the portal frame.
– Flint and Steel: Required to activate the portal.

### Step 2: Find a Lava Source
– Locate a lava source in the overworld or underground. It’s easier to find one in the overworld as it provides more space to build the portal.

### Step 3: Create the Portal Frame
#### Method 1: Using a Water Bucket and Lava Pool
1. Identify a Lava Pool: Find a side of the lava pool with at least four lava blocks in a row.
2. Place a Block: Stand directly behind one of the lava blocks and jump up three times while placing a block below you. This will create an L shape with one block on the edge and two blocks on the side.
3. Add More Blocks: Place one more block on the edge to complete the L shape. Then, place one block directly behind the fourth piece of lava and another one to the left of that block.
4. Add Water: Place a water block against the lava, making sure it doesn’t spill over. This will help you create the frame without the water flowing into the lava.
5. Remove Water and Add Lava: Remove the water block and dig out the blocks underneath. Replace them with lava, which will turn into obsidian.
6. Build the Frame: On the right side of the portal, build three blocks up and one out towards you. On the left side, build two blocks up and one out towards you, ensuring there’s a two-block air gap behind the blocks.

#### Method 2: Using Obsidian Blocks
1. Gather Obsidian: Collect at least 10 obsidian blocks. You can mine them using a diamond pickaxe or create them by pouring water over a lava source block.
2. Create the Frame: Place four blocks in a row horizontally, then another four blocks vertically, and finally, two blocks at the top to complete the frame.

### Step 4: Activate the Portal
1. Light the Portal: Use flint and steel to light the center of the portal frame. This will activate the portal and allow you to travel to the Nether.

### Optional: Enlarge the Portal
You can make the portal larger by adding more obsidian blocks around the existing frame, up to 23×23 blocks in length and height.