

郵便局で切手を買いました。
日曜日は郵便局が休みです。
国に荷物を送りに郵便局へ行きます。
"ゆうびんきょく(郵便局)" is in the lesson "Institutions" (Level 11), along with 12 other useful words. LinDuo has 180 topic lessons like this one, 2,379 words in total. Every word has an illustration, a transcription and pronunciation in a female and a male voice. Just 10–15 minutes a day is enough to learn them all. Free, and works offline.