9. Ireland
You won't need to worry about any language barriers when traveling to the gorgeous green hills of Ireland. Compact with easily walkable streets, Ireland's cities pack a lot of punch in a small amount of space. Plus, hop-on/hop-off buses and the capital city of Belfast's famous black taxi tours stand by. To see castles and the top sites like the Ring of Kerry, half or full-day bus tours can be arranged, most of which offer senior discounts.