Our house is situated on a steeply-sloped, narrow (50' wide) lot with only a small amount of flat land surrounding the house. There is an 8' deep concrete patio abutting the back of the house that covers 39' of the 50' width, with a stone retaining wall that runs the entire width of the lot on the other side. The remaining 11', which is on the south side, is unpaved dirt. The photo below is taken from the north end looking south (the dirt area starts just past the AC units).

Closer view of the dirt corner:

And another photo of the dirt corner from the side yard:

We have begun the process of eliminating the south side lawn (it is largely shaded by the neighboring house, so grass doesn't grow well) and turning it into garden beds with a walking path. We would like to turn the dirt corner into a seating area with a firepit, which would extend down the side yard to the window well pictured in the last photo above. We have consulted with a few landscape pros about this job. They seem to think this is a good use of the space, but some have expressed concern about using pavers or another impermeable surface because the existing patio already presents drainage challenges given the amount of impermeable surface. The existing patio does slope toward the dirt area and as you can see, we have a downspout/open drainage trough situation that needs to be resolved whatever we decide. The neighbor on that side has stepping stones over a dirt area that looks like it sits slightly higher than our existing patio.

Others have said the best plan is to lay pavers over the existing patio (to improve its appearance since it is badly cracked) and extend them over the dirt portion as well to create a single surface, but while we would love to improve the appearance of the existing patio, it isn't a priority at this time. We are fine with the idea of having two different surfaces for the main patio and the firepit area, and we would prefer to avoid the possible drainage problems that might come from using an impermeable surface. Decking was suggested but since we want a fire pit, we want something fire proof!

Our initial thought was use decomposed granite (or a similar crushed stone) for two reasons - first, to avoid creating further drainage problems, and second, so that if in the future we wanted to lay pavers on some or all of the area, we could use the decomposed granite as a base. However, the area is not level - it slopes downward toward the front of the lot (west) about 12-13 inches over the distance we'd be looking to cover (19-20 feet). Presumably we would need to add a step or two to make this work, but I don't know how this would look with DG. Is there an elegant way to do this? We would consider connecting the area to the planned garden path and would probably do the path in DG as well. Would love some input on this or other possibilities. Thanks in advance!