明暗之間的時空體驗，保留場所精神，尊重自然與環境共生
「THE DARK LINE 時空暗線」座落於北台灣牡丹－三貂嶺之間，總長3,192公尺。我們打開1985年即封閉的兩座舊隧道，在明暗之間，呈現牡丹與三貂嶺地帶的魅力，每段空間的視野、尺度、濕度、聲音、光、質感、生態都不一樣；伴隨環境再生的力量，在山林裡建構出魅力獨具的後工業地景。
隨著隧道重啟，百年前鐵道開通、礦業運輸盛況、到後期長年封閉的人文織理重現眼前。它不只是一條隧道，更見時間在此連續演進的痕跡。因此我們選擇透過一條路徑帶入，彰顯這些隧道內外原本就存在的空間特質，經設計轉化為可閱讀的空間，帶領更多人看見時光中被遺忘的記憶。
以充足調查為基礎，訂定介入策略，傳遞地方的自然與文史厚度
為維護現地空間特質，經過多次且多層面探勘，採用許多非碰觸、非破壞性的技術進行調查，獲得充足資訊以支持規劃設計策略，回應包含生態、隧道結構、地質、人文背景等各尺度的空間議題，方能讓參訪者真正體驗這裡已然美好的環境、蘊藏的文史厚度。
不抹去環境特質，保留可閱讀地貌紋理
隧道封閉三十七年無人使用，磚壁滲水、逕流填充整個隧道，隨著流水及沖進來的土石衍生有機且豐富的地貌，如積沙、積石、水紋等；隧道外則可看到基隆河谷景致、壺穴、舊鐵橋遺構、岩盤與其上的植被、野溪、現行的平溪線與宜蘭線等。
為了不破壞長期累積的自然狀態，本案設計將路徑高架化以保全既有連續地貌；參訪者走在鋼筋格柵高架棧道上，能閱讀到隧道內外多樣的動態地貌，感受從不曾停歇的環境脈動。
The Dark Line project participates in the networking of the cultural routes and the heritage sites. It closes a vast loop which connects existing cycle paths and the railway line between Sandiaoling and Mudan.
Industry abandons places with as much radicality as it invests in them. Built by a precise technical and economic system, industrial installations are emptied as soon as a more efficient system supplants it.
Over time, fauna, flora, hydrography, geology have made this site something other than a railway tube passing under a mountain, it is now a hybrid environment where the classic distinctions between nature and culture are blurred.
AN INTERVENTION STRATEGY TO EXPRESS THE HISTORIC THICKNESS OF THE PLACE
The challenge is not to restore the tunnel, but to preserve its current state and the historical richness of the place. The monumental industrial ruins abandoned to vegetation and bats, the tunnel mouths filled with silts and rocks, crossed by seductive flows, etc. These all make us feel the power of the change of times.
A UNITARY VOCABULARY WHICH PRESERVES THE IDENTITY OF EACH TRANCHE
Material uniformity brings out the diversity of the place including shaded forest in the eastern section, tunnel with its flowing water, sows silting up, and accumulations of stones, lush vegetation between the two tunnels, mirror of water, and footbridge in the trees along a steep cliff.
AN ELEVATED/SUSPENDED FOOTPATH BECOMES A MEDIUM FOR PEOPLE TO PERCEIVE THE SITE CHARACTERS
The footpath is detached from the natural ground or surfaces, leaving a continuous protected space for flora and fauna to minimize the impact on the existing environment. A transparent pavement made of steel rebars reveals water flows, silting up, accumulations of stones, geological traces and vegetation below. The footpath is a medium for people to perceive the site characters.