Land locked trade links?

If you are landlocked, how do you connect to your civ's homeland trade network, that is if you cant build/use a harbor?

I was settling into the homeland dominated by Isabella and William. In between me and them was a large island with 8 CS. I had built a rail across it so units could embark-swim-railroad-swim to Isabella land, but decided I should settle a city in the centre so I could maintain control, stuff some Ziggyanity (my religion) down their throats etc.

Later, it turns out there was 6 oil and 10 aluminum in the southern part, so I brought over another settler to lay claim to it. Luckily at the last second I moved the settler 1 tile south to the coast and was able to connect the goodies via a harbor.

What if I hadn't? Is there some other way to connect for trade? Airports used to do this as well but they are gone. Would the only other alternative be to conquer one of the CSs?

Still later, one of the CSs wanted a road "to my capital", and since they had oil and uranium I tried to oblige and be all friendly like. They never recognized it though. The road went from SIngapore to City A which in turn was connected to City B which had a harbor. Both my cities showed the 3ball-triangle symbol for trade networked but Singapore never recognized it. Any ideas?

Thanks!

Did you build the road all the way to Singapore's city, or just to Singapore's culture borders? If the latter, it's not good enough.

Yea, I should have mentioned I made sure of that. It turns out (apparently) that when they request a 'road to your capital' the really want a road and if they are on an island or different continent, then you just cant complete the quest. All of CS in this game which are connected to the trade network show it as a an uncompleted quest (4 or 5 total).

What I was really asking about is if there was an alternative to Harbors...it seems a bit one dimensional that trade never evolves from relying on harbors.

Thanks!

Hmmm, I can't say I recall ever getting a "build a road" quest from an island CS.