Hi xefline,
Some of the perspective is a little bit off on your gate, it's especially noticeable with the decorative things on either side of the anvil insignia since they don't line up with each other.
If you are using photoshop I'd recommend setting up a simple perspective grid(if you haven't already) or doing your rough sketch on a smaller scale so you can fit the vanishing points onto the canvas before up-scaling the image and doing your final line work. If you are using clip studio it has a built in perspective rulers/grids which is really handy for stuff like this.