Tell al Ashari located on the slopes of the Yarmuk valley,
and is identified on the basis of a few archaeological finds with the Dion of the Decapolis. The tell possessed one of the most striking features for the definition decapolis cities, a theater.
The existing settlement mound is archaeologically explored and clearly shows how entire areas, such as the aforementioned theater were ablated over the centuries. The well-researched and readable essay by A.Kropp about the Tell "Dion of the Decapolis" does not find opposite opinion to the location of Dion on the Tell al Ashari in the summary. but the episode on the "Dia" of Damascius in "the Life of Isidore" on closer inspection even fits better to Tell Esh Shehab and the neighboring Zeizoun. A. Kropp himself asumed that probably Taffas, located east of Tell, was more the urban center than Tell al Ashari.
The most used evidence are two almost unused / new coins from Dion, which were found in a grave northeast of the Tell,in 1931 by H.Seyrig. In any case, Tell al Ashari is an important location within the Decapolis.
Another unique feature of Dion is mentioned here and is under the point the first dioceses here again briefly illuminated. While all the well-known cities of the Decapolis and also serveral of the larger towns in it counted among the first mentioned bishoprics of Christianity, simply and solely Dion is missing from this list. The City of "Dionysias" of the diocese lists is clearly identified with today's As Suweida, southwest of Qanawat and todays capital of the entire region. All this speaks in favor of a "lost" place as Damascius describes it of "Dia".
But we have no real reasons for that, for example, was Abila also not located directly on an old main road and only connected to the Street network via a side connection. So decoupling from trading, during or at the end of the Decapolis period, is not a plausible reason for the abandonment of the City Dion. Perhaps, the proximity and location of Tell al Ashari, Tell Shehab, Zeizoun (Kafr Zizia), between the dioceses: Abilenus (Abila), Adraenus (Deraa) and Neapolis (Sheikh Saad) and Nevensis (Neve), led to the deterioration of the political and trading situation of this Place.
At the time of the Decapolis the Tell definitely represented only the Acropolis of the place, this was, as also to be taken from my remarks about the Dekapolis, this was also quite certainly in the area of ​​the Dekapolisregion "Gabe" after Plinius the same.
Despite its prominent position on the steep slopes and the remarkable waterfall, this tell also had to rely on water via an aqueduct. Only then could buildings lying here be supplied with running water. Gottlieb Schumacher describes the only provable evidence of this supply with an aqueduct channel coming from the north (Ain el jisr). In the immediate vicinity of the location are also the sources of Birket el Ashari (Ain el Ashari and Rouajdat) and the Ain Gzouli.
The fact that these sources fedded the Qanat Fir'aun can not be derived, either archaeologically or from a surveying point of view. Especially since in addition to the non-existing height connection, the need for such a route were definitely not given.
As the richest source (the high source / Ras el Ain) of the whole region it supplies the Bahret el Baddje in Muzeirib further south and this source lies in the immediate vicinity of the verified Qanat Fir'aun line. 

Here you can see the exact geolocation of the city area.