No, there are no storage options.
2 things you can do though: bury your wallet/phone in a zip lock bag under/near your towel or buy a personal such safe such as this https://www.amazon.com/dp/B07QD8DDLK/ref=cm_sw_r_cp_apa_glt_fabc_G9DKG10D1QRXQ3T9V4P3
You would still need something to secure the safe to but it would deter someone from doing a snatch and grab.