"Usual types of containers" include magnetic bottle tops, Frisk, Mintia boxes, home-made envelopes, etc. "Usual places" may be white crash barriers, guardrails, gate lock boxes, bridges, cages, structures, etc.
A long time ago there was a very important temple here, Hashimotodera, which was built during the Nara era (between 668 and 749). Now it's gone, and all that remains are this stone monument, and this sign. And now there's a small magnetic cache, down the steps, near the white fence.