Fences and Gates - how do you install a gate when you cant go down more than 1 ft?

I had to take down 4 sections of my fence for other work but now it's time to put them back up and i wanted to put a gate in and also bury the supports deeper this time. I didnt have a gate before, just 8 ft sections of fence in using those yard stakes for 4x4s

I think i must have an old patio or something under my grass in one location because whenever i drive any test stakes into the ground at certain places, the thing wont go down more than a foot. So where i need a gate to go, at my rear sidewalk to my back door, it cant be installed. From the last fence post it's 8 ft into my yard (ie i definitely could have a very solid post put in there) and actually it's about a 2ft hill being held back by some concrete block but that can be easily removed.

I dont want an 8 foot gate spanning that distance though and it's very important to have privacy so i cant use just lighter material like chain link. And dont even know how such a thing in my 'wood fence' material 8 ft long could be supported. but im at wits end trying to figure out what to do there.

Any suggestions on what to do when you can only go down a foot? going further towards my back door is a possibility but i'm pretty sure all along my existing sidewalk is that same concrete patio underneath it all. I remember years ago trying to dig closer to the house and ran into the same issue. And the fence/gate needs to be high and private because it's enclosing a spa area. I already have the other side of the fence up my embankment in the yard and thats weathered everything just fine.

Assuming a concrete slab under the dirt rent a core drill or electric pavement breaker and drill a hole in the slabe to fit the post diameter or bust out a hole and dig to needed depth. If you do the former you may want to drive the post into the dirt below the slab.

Dig the area out and see EXACTLY what you are dealing with.

you might want to contact a utility locator before you do anything else. While it is unlikely it is a utility, there have been stranger things seen.

do you know where your electrical service lateral is?

not a utility. All electrical lines are overhead my backyard and i just had my entire house excavated so know where everything else underground is. I've been digging thru this forum looking for similar problems and may try a sliding gate based on some other postings....but i dont know how much structural integrity would be needed because until my other 2 fence sections are up, i dont know the line of sight issues for any gate (ie is the standard 6 ft good enough or do i need higher). But if i just did the custom gate it would only need to be 5 ft wide then would slide into my 2 ft concrete block wall holding up that part of the yard.

Or would i just be able to use a yard stake 1 ft into the ground to be the 'receiving end' of the gate locking mechanism whatever that would be. There would be no real pressure on that post so i guess it's possible. Matter of fact, now that got me thinking i couldl have a fence running from that 'locking post' into my yard and in addition to the end post in the yard, i would add another post mid section. Therefore the fence could be tied into the locking post (that has only one 1st in the ground) and actually even add support to that locking post. Hmm just might work!

I know that's hard to visualize. Ill try to find a pic sometime and mark it up