Important to know is that they are compound fields, part of custom geolocation fields or the address fields.
This is also how you'll find them in the SOAP API:
Address field:
<element name="BillingAddress" nillable="true" minOccurs="0" type="tns:address"/>
<element name="BillingCity" nillable="true" minOccurs="0" type="xsd:string"/>
<element name="BillingCountry" nillable="true" minOccurs="0" type="xsd:string"/>
<element name="BillingCountryCode" nillable="true" minOccurs="0" type="xsd:string"/>
<element name="BillingGeocodeAccuracy" nillable="true" minOccurs="0" type="xsd:string"/>
<element name="BillingLatitude" nillable="true" minOccurs="0" type="xsd:double"/>
<element name="BillingLongitude" nillable="true" minOccurs="0" type="xsd:double"/>
<element name="BillingPostalCode" nillable="true" minOccurs="0" type="xsd:string"/>
<element name="BillingState" nillable="true" minOccurs="0" type="xsd:string"/>
<element name="BillingStateCode" nillable="true" minOccurs="0" type="xsd:string"/>
<element name="BillingStreet" nillable="true" minOccurs="0" type="xsd:string"/>
Custom GeoLocation field:
<element name="sdry__GeoCoordinates__Latitude__s" nillable="true" minOccurs="0" type="xsd:double"/>
<element name="sdry__GeoCoordinates__Longitude__s" nillable="true" minOccurs="0" type="xsd:double"/>
<element name="sdry__GeoCoordinates__c" nillable="true" minOccurs="0" type="tns:location"/>
Rest API returns the same combination of fields.