Which Mac address should be used in Ethernet Header?

Consider that we are working on a Local Area (LAN). In this case, I use the mac address of the destination device for destination MAC address for ethernet header. This is working.

But, I don't know, which Mac address should be used on Global Network (WAN).

• Mac address of the Router of destination device?
• Mac address of the Router of source device?
• Mac address of the destination device?

I draw a schema to explain my question. But I'd needed at least 10 reputation to post images.

I tried several combinations and I realized that in Wide Area, the destination Mac address in the ethernet header should be the default gateway's Mac address of the device. In my stuation, it was "Mac address of the Router of source device".