[Fiction question] Where can you rent or secure an always-accessible storage locker or lockable unit large enough for a gym bag?

If you want to store a gym bag that you can get at anytime, but where you can go in and out freely and anonymously, where do you go? It doesn’t literally have to be 24/7 as long as there’s ready access during the day, including weekends.

You’re definitely not keeping the bag at home or in your car.

You can’t keep the bag securely at work, and you’d attract attention popping in and out. At the Y or an athletic club, too, people will know you and notice that you go right in and out.

There’s going to be a parking problem at a downtown bus station. At the airport, you’ll have to pay for parking, and it won’t be very close to the terminal. Those are major disadvantages.

If you just rent a large postal box at a mail drop, can you keep whatever you want there?—use it as storage? Are there units large enough for a gym bag?

Even better if this storage unit is in a place where you can also change discreetly into the costume you keep in the gym bag, without attracting special notice.

Bonus points if it’s a really creative location such as a church, a hospital, or a tourist destination.