I was able to enter the structure, by having a UA in my SRV cargo. The interior was mostly destroyed/caved in but there were some Thargoid uplink devices, which I was able to scan. Lots of barnacle spikes as said above, some MAs and materials to be had. Also a canister-like thing which scanned as "Thargoid Resin" which I've not seen before.
How far were you actually able to penetrate into the structure? I helped a group get in tonight and for both of the openable portals, the tunnel was blocked by cave-in just a few meters past the threshold. We couldn't get into the interior tunnels at all. Is that consistent with what you saw?