How to specify more than one areaServed (eg multiple municipalities) for a LocalBusiness?

A lot of businesses serve multiple municipalities.

How should this be expressed in https://schema.org/areaServed (JSON LD)?

<script type="application/ld+json">
{
  "@context": "https://schema.org/",
  "@type": "Service",
  "serviceType": "Weekly home cleaning",
  "provider": {
    "@type": "LocalBusiness",
    "name": "ACME Home Cleaning"
  },
  "areaServed": {
    "@type": "City",
    "name": "New York"
  },
... ?
</script>

Should it be:

"areaServed": {
        "@type": "City",
        "name": "New York"
      },
"areaServed": {
        "@type": "City",
        "name": "Buffalo"
      },
"areaServed": {
        "@type": "City",
        "name": "Syracuse"
      },

Or something like:

"areaServed": {
        "@type": "City",
        "name": "New York",
        "name": "Buffalo",
        "name": "Syracuse"
      },

Or something else?

Solution

City is a "More specific Type" of "AdministrativeArea" according to schema.org documentation, so nothing wrong with using that.

(unfortunately haven't got enough points to write this as a comment under nikant25s comment but thought it was important to mention)

I would write something like this: 

"areaServed": [{  
  "@type": "City",  
  "name": “New York”,  
  "sameAs": "https://en.wikipedia.org/wiki/New_York_City"  
},  
{  
  "@type": "City",  
  "name": “Buffalo”,  
  "sameAs": (the Wiki-page for the right Buffalo)  
}],

Since there are a lot of cities with the same name it’s probably good to use the sameAs property to specify which one you mean :)