There are only three towns within the park boundary though several more immediately beyond it. Dolgellau is the most populous followed by Bala on the eastern boundary and then Harlech overlooking Tremadog Bay. More populous than these is the town of Blaenau Ffestiniog which is within an exclave, that is to say it is surrounded by the national park but excluded from it whilst the towns of Tywyn and Barmouth on the Cardigan Bay coast are within coastal exclaves. Llanrwst in the east, Machynlleth in the south and Porthmadog and Penrhyndeudraeth in the west are immediately beyond the boundary but still identified with the park, indeed the last of these hosts the headquarters of the Snowdonia National Park Authority. Similarly the local economies of towns of Conwy, Bethesda, and Llanberis in the north are inseparably linked to the national park as they provide multiple visitor services. The lower terminus of the Snowdon Mountain Railway is at Llanberis. Though adjacent to it, Llanfairfechan and Penmaenmawr are less obviously linked to the park.