How to Make an Epic Harry Potter Castle Wall With a “Fat Lady” Secret Entrance (Easy DIY Party Decor)

Create a magical Harry Potter–inspired castle wall with a hidden Fat Lady walk-through portrait using simple materials and budget-friendly DIY techniques. This step-by-step tutorial is perfect for themed parties, Halloween decor, or imaginative play spaces; and it’s easier than it looks! Ideal for parents, party planners, and creative DIY lovers looking to wow their guests.

1. The Magic Behind the Project

One of my daughters decided she wanted to have a Harry Potter themed birthday, since she’s a winter baby right after Christmas we usually travel and this was her first friend party she was having and I wanted to make it feel extra special! As she is a proud Gryffindor, I wanted to create a “Gryffindor common room” for her and her friends to play in and it wouldn’t be complete without the Fat Lady portrait! And I wanted it to feel just as magical as the movies so I set out to make an actual portrait they can walk through and be transported to the Gryffindor tower.

For those of you that don’t know ‘The Fat Lady’ is a magical portrait in Hogwarts castle that the Gryffindor students give a password to and then walk through to their own private common room. Every Harry Potter fan knows The Fat Lady! This project can easily be tweaked to make your own secret private door entrance for any theme party, Halloween or just a magical play room experience! So if you’re not a Harry Potter fan- don’t fret!

2. What You’ll Need

• Base structure (foam board or large cardboard pieces/boxes etc.)
• 2-4 plastic tan colored shower curtains ( I snagged mine at Dollar Tree)
• 1-2 plastic gray colored shower curtains
• Printed or painted Fat Lady portrait printed wizards in frames
• Cutting tools
• Modgepodge or Elmer’s glue and a paintbrush
• Best brown tape ever

💡 Tip: You can also paint your faux stone wall as well! I was just going for quick and easy!

3. Step 1: Building the Castle Wall Base

We have a living room in our basement that serves as the kids play area and a little hallway that leads to it. I decided to wall off this hallway to make the ultimate grand entrance through the Fat Lady portrait, you could easily do the same with any space or even create this wall in an open doorway or between rooms.

Measure how tall/wide it needs to be to fit the space/hole and add several inches on either side to allow for attachment. I built the wall right up to the ceiling and to the floor, so you don’t need to add any extra to the top and bottom of the piece.

I had several large cardboard boxes I broke down to fit my space and taped them together with my favourite brown craft tape both on front and back so it felt solid. Once everything is taped together ensure it fits your space properly before moving to the next step. I knew where I wanted my door to go and which side I wanted it to open on, and added an extra layer of cardboard to the side that would serve as the “hinge” for extra support as I was worried the kids might be rough on it!

Step 2: Making the Fat Lady Walk-Through Portrait

I found a photo of the Fat Lady on the internet and blew it up and printed it on my home printer, taping several pieces of computer paper together so it was large. (we’ll add the frame later). You can also buy her as poster in various places or purchase her as a print!

Using your Fat Lady as a guide decide how big you want your doorway to be. I wanted mine to be smaller than a normal door so adults would have to duck to get in, but big enough it wouldn’t be an issue to get through. Mark off the shape of your door on the cardboard. IMPORTANT: leave one side of the door completely attached so the cardboard stays intact, this will help make sure your wall and door are stable and last! I made a rounded top and then just a straight shot down to the bottom.

I modgepodged my Fat Lady print out to the cardboard in the center of my door. I also used modgepodge on the top of her picture to give her some texture so she looked painted and not printed! Elmer’s glue would also likely work here! Let completely dry before moving on to the next step.

💡 Pro Tip: Trim the bottom of the door a little bit higher than the rest so it doesn’t catch on the floor and isn’t being dragged to open. This will help keep the integrity of your piece.

Step 3: Creating the Stone Castle Look

I was too impatient to paint my wall and let it dry before the party, so I went with a quick cheat that actually turned out really well! I snagged some cheap plastic shower curtains from the dollar tree (you could sub out so many different products here, poster board, construction paper etc.) I got a couple tan colored ones to act as the stone grout color. Just simply wrap your entire faux wall in the shower curtain (cutting out the door and around the Fat Lady) and taping it into place. I wrapped the curtain around all the edges and taped to the back it made this step super simple and quick and gave it a clean finish in the front!

Next I used the gray shower curtain to make my stones. I simply folded it several times to cut multiple layers at once and cut out different sized and shaped stones. It was very quick work! I laid the pieces down until I was happy then modgepodged them onto the other shower curtain. I just worked my way out from the fat Lady portrait to the edges! I was really pleased with how well this step turned out!

Step 4: Assembling & Styling the Final Look

Next is just some finishing touches! You can repeat the same process for the back, but if you use shower curtains you can just cut them the exact size of your wall and glue it down this time so no raw edges show on the front. I had a faux brick tarp handy and we just cut it out to fit the shape and taped it down on the back side.

I printed out some wizards and witches I found on a google search already shown in frames and cut them out and taped them onto the wall around the Fat Lady portrait. Made a quick cardboard frame for the Fat Lady portrait, painted it yellow and then taped it up to frame her in!

Once everything is hung and dry, you’re ready to install your wall! Tape your structure to the wall and ceiling with brown tape on the back side of the faux wall until it’s sturdy and in place.

Tips for Success (What I’d Do Again)

I was so pleasantly surprised that my shower curtain idea worked out, I had been looking at faux stone stickers but to cover the whole thing would have added up really quickly. I love how it turned out and it kept this project an easy do for anyone! Next time I might cut the door, wrap the whole wall and then add the fat lady on top. But the other way around really wasn’t that big of a deal!

If you’re particularly artsy or have more time, painting it would be a great touch and make it feel so much more realistic! Go wild!

Time estimate + skill level: All in all this project took me one morning to complete and that was with me making it up as I went, so with these laid out instructions I think someone could knock it out in a couple hours depending on their detail choices! I would say about moderate skill level to complete.

Final Reveal + Party Reactions

The kids and parents alike loved this feature and had everyone talking. It really made the kids feel like they had their own special secret space and The Gryffindor common room was a complete hit- even for non Gryffindors! I would certainly recommend you give this a try if you’re looking for that magical touch for your next event or party! Would love to see photos of your version!

---

If you loved this project, save it on Pinterest or share it with a fellow Harry Potter fan! Follow along for more creative DIY party ideas and magical builds.