Need ideas on building faux rock built-in bench seat

Good morning!

I come here today because I have a rather ambitious project formulating in my head and need some suggestions or ideas on how best to execute it, particularly with cost and skill level in mind. I have a rather low budget and have never done anything like this before. That said, from what I have seen online I believe it's totally within my range of ability to figure out and do, so that leaves me now in need of help concocting a design plan and one that will work within a low budget.

The plan:

I have a backyard tiki bar that sits on a 23 ton sand "beach", and as we've entertained it's become apparently I need to really consider some seating for guests. I do not want to have to drag chairs all over and have the sand cluttered with that ,other than a few nice adirondack chairs around the fire pit. My first project immediately this spring is building a raised garden along one side of the beach's edge. Last year my focus was the entrance side, we installed a boardwalk and landing and along that there is a garden bed with plants and large decorative rock,

I cannot really dig into the ground along this other side (I tried, believe me) but the ground is very rooty so I decided last summer I need to build a raised garden bed there so that I can actually put an assortment of plants in that space and achieve that tropical look I desire.

Until recently I wasn't sure what kind of retaining wall, but down the road we are going to build a faux rock waterfall at the far side of the beach that is styled after those like you see around Disney and such. After visiting Orlando a few weeks ago, I came home armed with a plan for my raised garden bed, that I will create a retaining wall in the same style of the future waterfall, building it with concrete to look like fake rock, carved and such to achieve the look. The waterfall will sort of taper down with a series of built in planters and lighting and lead into this garden space.


I have been (preceding this garden plan) exploring many options on how to use this space, and felt frustrated that I am abandoning my options for built-in seating around the beach. I had planned, originally, to just do built-ins to match the boarwak and felt it did not incorporate well into the plans for landscaping and plants so what do I do?

My boyfriend embraced an idea we both had as a way to do both, just have the garden behind the seating and the bench sort of taper off into the start of the waterfall. I still wasn't convinced, but he's hanging onto the original plan of building seating that can open up like a storage box to house the cover we use on the sand, to eliminate the hassle of that.


My idea now, and I am pretty set on it, is proceed with the raised garden bed with a faux rock retaining wall, and make built-in seating also in the faux rock on the beach-side of the garden, that again, is connected to the waterfall feature.

I have attached a sketch and some inspiration images.

I have NO idea how to proceed with a design plan for the bench. It will clearly need to withstand use, the weight of people (even larger ones). I am thinking building a base with cinder block but I hate using them. Or building the entire foundation from heavy wood and just covering that with the concrete?

My boyfriend ins't going to be happy, he is concerned with what it will cost him, if it is something I will end up dragging him into helping with while he has his own projects to do inside the house and I think mainly, how ugly it will be in the process and how long it will remain an eyesore to neighbours before it is finished.

 

Do you have a short version or just a question?

 

This appears to be a pretty ambitious project and I would think a bit more than you can handle alone.
I'd recommend calling a landscape engineer and try to get a firm idea and cost for the job.