You can have site to site IPSec VPNs to non-Meraki kit.  This is the instructions on setting it up. https://documentation.meraki.com/MX-Z/Site-to-site_VPN/Site-to-site_VPN_Settings#Non-Meraki_VPN_peers   However I must warn you, Meraki MX is not strong in this area.  You can only do basic subnet to subnet VPNs (nothing that involves NATing part of the address space) and the tools to diagnose things when it is not working are weak. ... View more